It's not at all unusual for a gun's bores to be proofed tighter than its nominated cartridge. If it was proofed at 9 then .79ish isn't such a lot of choke. Sounds pretty normal to me.
As to maker: there may well be some initials discreetly stamped on barrels, locks etc in hidden places that require disassembly to get a look at that offer some clues; there may also be some stylistic clues common to other makers. But then, if it had a name on it, any price tag would probably reflect that with a premium
