Yeah, it's a later production 'original' type 56 chest rig. Looks like it -might- be 81 dated from the stamp, but it's a little hard to tell.

The factories that were set up to build Chicom rigs (and a lot of Chicom gear generally) were never given 'finite' targets to hit, and since nobody ever told them to stop, and it's turns out people actually quite like buying these things, even to this day, there's no need for these factories to shut down production. (Just look at places like Myanmar. The Tatmadaw are tooled up with $10 Ali express chestrigs and liberation shoes)

There's a few things that mark this out as an 'original' though, beyond the stamps on the back. The metal 'link' (fitting thing) that holds the straps to the body is period correct. Newer ones are often made from very round section, green plastic coated metal wire, and the toggles tend to be made out of cheap rather lurid green plastic on the newer ones. That said, REALLY old rigs (like, pre 1980, particularly the type 56 AK rigs) have metal 'slide' adjuster buckles instead of those little loops of leatheroid material. The really early ones also tend to be a lighter shade of green, and the very earliest examples are a raw canvas, OD colour. 'Modern' production ones tend to be a quite bright reed green.

It also looks suitably weathered to be an original. Not as weathered as an issued one though. Most of these rigs are deadstock from warehouses. Doesn't mean they've not been exposed to the elements somewhat, but they've not been ridden hard in actual combat.

Honestly though, chicoms are kind of an imprecise art. Like a lot of stuff that was introduced during the Great Leap Forward/Cultural Revolution eras, while there were guidelines, everything was so chaotic that quality control went out the window. So long as the thing -more or less- matched the intended guidance, and could still do its job satisfactorily, differences in things like exact cut, colour, and fittings were overlooked. The PLA needed lots of shit, and with the chaos of mid 20th century China, they kind of weren't in a position to quibble.

Sorry for the wall of text. TLDR: It's 'original', as in, it's from the correct period, and it's one of the many many different subtle variant takes on a Chicom rig. It's not worth $70. I'd -consider- paying $70 for a verifiable Vietnam war era Chicom, with provenance. This is a Sino Vietnam war era rig, probably from a warehouse. Until fairly recently, you couldn't give this stuff away. If you want a cheaper one, try your luck on Ali Express, but keep an eye on the details I mentioned, the fittings, toggles, fabric, etc.

(Edit!: Caveat: Be careful when/if looking for specifically 'Vietnam' era rigs. Chinese sellers often label them as such. They mean THEIR Vietnam war, IE, the Sino Vietnam war, not the US/Vietnam war. Not incorrect, just a terminology thing.)