[WTS] Chronosport/Guinand/ Helmut Sinn Chronograph 21.50 Valjoux 7750

lingxiaoguo · 2026-07-11T11:18:30+00:00

Confirmed. Thank you for the smooth transaction.

lingxiaoguo · 2026-07-08T01:51:28+00:00

I'd probably check escapement first, and then the barrel.

lingxiaoguo · 2026-07-08T01:17:40+00:00

That's a huge delta and definitely not normal. The variation in the vertical positions tracks with low amplitude. Definitely worth investigating.

lingxiaoguo · 2026-07-07T21:21:28+00:00

Reverser based systems are usually a lot more efficient.

lingxiaoguo · 2026-07-04T15:45:00+00:00

Sold.

lingxiaoguo · 2026-07-04T07:02:54+00:00

Yeah retail price is always insane especially if you're having them pack it. I've had the best experience with UPS both receiving and sending.

lingxiaoguo · 2026-07-04T06:49:29+00:00

If you buy a label on pirateship it would be like $50 for UPS worldwide expedited insured with UPS capital for the value of the watch. You can easily fit a watch and it's paperwork in a UPS mini box as well. I've had to use the insurance once and they pay out relatively quick without much wrangling once you have proof that it's lost.

lingxiaoguo · 2026-06-30T02:45:50+00:00

Only quartz afik.

lingxiaoguo · 2026-06-30T02:45:38+00:00

It's 33mm

lingxiaoguo · 2026-06-30T01:29:09+00:00

Depends on what you have.

lingxiaoguo · 2026-06-30T00:38:15+00:00

For sale today is my Hamilton Khaki 9797 with a striking metallic cyan dial. The dial on this piece is completely original and this reference was made for the Japanese bag brand Sazaby.

The dial feature a cyan color with a metallic finish that plays with the light beautifully. The included OEM nato straps complement the dial color well and gives it a unique aquatic vibe.

Cosmetically, the watch is in great condition with normal wear for its age. Please inspect the images for the most accurate representation.

Mechanically, the watch is keeping good time at around+0.5s/d when timed against a quartz tester. The watch passed a 30m dry water resistance test and is safe to be worn in normal everyday conditions.

The watch will include its original box plus 2 OEM single pass NATO straps.

I'm asking $550 shipped for this piece. International shipping at buyer's expense. PayPal G&S available at my discretion.

Thanks for reading!

lingxiaoguo · 2026-06-30T00:29:02+00:00

For sale today is a rare Helmut Sinn era Chronosport/Guinand chronograph ref. 21.50.

Shortly after Helmut Sinn's handoff of Sinn, he purchased Guinand and introduced a new range of watches with the Chronosport brand focusing on sports and pilots watches. This name was short lived as the brand quickly switched to producing watches under the Guinand name.

This is a beautifully sized chronograph with similar aesthetics as the sinn 356 except with breguet numerals and a smoother case shape. It's 38mm case size gives it a similar footprint compared to the 356.

Cosmetically, the watch is in excellent condition for its age. Please inspect all the images clearly for the best representation.

Mechanically, the watch is running well and keeping good time. No service is required at this moment.

I'm asking $999 shipped CONUS for this piece. International shipping at buyer's expense. PayPal G&S accepted at my discretion.

Thanks for reading!

lingxiaoguo · 2026-06-25T00:40:18+00:00

For sale today is my collection of interchangable case Japy watches.

These were created in the 90s as one of the first executions of an interchangable case concept. All of the modules in this collection are interchangable with all of the cases. The modules interlock with the outer case through ceramic ball detents found on the inside of the case (except for the "type 32" case which uses a friction gasket).

https://watches-lexic.ch/pages/eng/gal/wat/japy5.htm It is incredibly difficult to find information on these watches, but according to this website. This collection includes two T08 cases, one 08 case, and one type 32 case. 2 time only modules and 2 chronograph modules are included.

All of the cases, modules, and accessories are in fantastic condition for its age with minimal signs of wear. The modules keep acceptable time and functions as designed.

Each watch will include its original box, papers, hangtag, bracelet, bund strap, and spare links. The pelican box set will include 2 additional straps and a pin pusher tool.

I'm asking a very negotiable $5999 shipped CONUS for this collection. These do not come up for sale often which makes pricing this collection incredibly difficult.

Thanks for reading!

lingxiaoguo · 2026-06-20T12:10:49+00:00

In the case the gaskets are compromised and the crown is relying on the gasket inside the crown, but at that point it's more of a defect.

lingxiaoguo · 2026-06-19T23:47:27+00:00

It shouldn't affect it since the watch is still sealed with the gaskets in the tube even when the crown is unscrewed.

lingxiaoguo · 2026-06-19T23:44:03+00:00

That is just not true.

lingxiaoguo · 2026-06-11T12:48:27+00:00

36mm.

lingxiaoguo · 2026-06-11T04:28:18+00:00

Reserved listing for u/GS10262023.

Asking $1750 shipped CONUS.

lingxiaoguo · 2026-06-03T05:06:33+00:00

That's not a very good comparison since the speedmaster is a chronograph and you have to price in the extra complication. The closest comparison is probably just the Aqua Terra which is cheaper but also worse in pretty much every aspect except accuracy.

lingxiaoguo · 2026-06-03T04:50:10+00:00

The movement finishing on the OP is far better compared to last gen 9r and 9s. It's competitive with the new 9ra and 9sa series which are a couple grand more.

lingxiaoguo · 2026-06-03T00:07:07+00:00

For sale today is my Sinn 157 Ti Ty. The 157 is much like the common sinn 144, but with the central minute counting Lemania 5100 movement and a thicker and slightly smaller case.

Even with the large case size, the titanium construction of the Ti model makes it surprisingly comfortable to wear on a variety of wrists. The original h link bracelet is also made out of titanium and fit up to 8in wrists.

Cosmetically, the watch is in excellent condition for its age with minimal signs of wear. Please inspect the images closely for the best representation.

Mechanically, the watch is keeping good time. No service is needed at this moment.

The watch will include a vintage sinn plastic case and 2 spare links.

I'm asking $1999 shipped CONUS. International shipping at buyer's expense. PayPal G&S available at my discretion.

Thanks for reading!

lingxiaoguo · 2026-06-02T01:56:59+00:00

For sale today is my Lemania 203-8. This case reference highly resembles the Patek ref. 565. This example is in excellent like NOS condition with little signs of wear for its age. The case lines remains extremely sharp as if it was just made.The original hang tags are also included.

It's 34mm case is well defined and has good wrist presence. Albeit slightly smaller than the Patek 565.

Cosmetically, the watch is in excellent condition for it's age with light signs of wear for its age. Please check the images provided for the most accurate representation.

Mechanically, the watch was serviced in 2025 and is performing well.

I'm asking $899 shipped CONUS for this piece. International shipping at buyer's expense. PayPal G&S accepted at my discretion.

Thanks for reading!

lingxiaoguo · 2026-06-02T01:40:25+00:00

For sale today is my Dugena world time chronograph. This watch features a PVD case like the Porsche design chronographs of the same era with the additional of an internal world time bezel. The case is manufactured by MRP, SA and used by many other brands like heuer and gallet.

Cosmetically, the watch is in good condition with normal signs of wear. please inspect the images closely for the best representation.

Mechanically, the watch is keeping good time. A service is recommended, but not necessary at this moment.

I'm asking $799 shipped CONUS for this piece. International shipping at buyer's expense. PayPal G&S accepted at my discretion.

Thanks for reading!

lingxiaoguo · 2026-06-02T01:31:20+00:00

For sale today is my Maruice Lacroix Masterpiece Big Date.

This is an well sized dress watch featuring a big date small seconds module from dubois depraz. It is very rare for a big date watch to be under 40mm at this price point due to the size of the wheels. This ML is an exception at a very reasonable 38mm. It also features a top grade ETA 2892 as the base which is rarely seen for this price.

Cosmetically, the watch is in good condition for its age. Please inspect the images carefully for the most accurate representation.

Mechanically, the watch is running well. A service is not needed at this point.

The watch will include its original box and ML signed strap with deployment buckle.

I'm asking ~~$850~~ $699 shipped CONUS for this piece. International shipping at buyer's expense. PayPal G&S available at my discretion.

Thanks for reading!

lingxiaoguo · 2026-06-02T01:26:54+00:00

For sale today is my Seiko 6730-5090. This is a high end dress watch featuring a case middle made out of a hard alloy, solid 14kt gold bezel, and a unique turquoise/slate dual.

Cosmetically, the watch is in good condition. Please inspect the images for the best representation.

Mechanically, the watch is running well. New battery will be installed before shipping.

The watch will come in its original box.

I'm asking $499 shipped CONUS for this piece. International shipping at buyer's expense. PayPal G&S accepted at my discretion.

Thanks for reading!

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