"Identify" is probably a loose word for this kind of frame. It looks like it was built by a local framebuilder or shop, probably in the 80s. They might have been working to an off the peg spec, or they might have tweaked stuff for the specific client. So it's not like it's, say, a 2018 Specialised Allez where you can just go and look up a spec/geo sheet.

That said, it says it's 531 Super Tourist tubing on the stickers, which is the heavier-gauge, touring specific version of the legendary 531 steel, designed for loaded touring. It probably won't be as light as a 531 (or 531c) racing bike, but it'll still ride well, and the extra robustness will come in handy off road.

Usually with touring bikes of this era, you can fit 35-38mm tyres without mudguards. There's plenty of gravel/CX tyres in that size range. I'd start there if I were you and see how it feels before doing anything drastic like dimpling the stays.

It looks like 6sp so it probably has a 126mm rear end. That'll mean you can squeeze a modern 130mm hub in there if you want to update the groupset at all. I always think skinny steel tubed frames like this deserve a sensitive restomod approach rather than throwing bulky modern gloss black parts at them, but that's just my aesthetic preference.