hello trying to identify this sxs, side plate says International Guns MFG CO and has find Damascus finish on top of the barrel and ive taken a picture of the proof marks under each chamber any help would be appreciated im sure it has very little value but i don't know anything about it thanks!!!
You are correct in these guns having little monetary value. These double guns, commonly called "hardware store guns," were built in large numbers for the North American market, and many, if not most, were built in Belgium. Yours was, and the proofs give some information. Reading them top to bottom (or left to right in your photo), these are: the left-hand barrel is choked; both barrels had a nominal bore of 18.0mm, which is very tight for a 12 gauge (18.5mm or so is more typical), and 0.4mm of choke, tighter still; provisional barrel proof; inspector's mark; second provisional proof; 'perron' mark, for proof of the breeching system; 12 gauge chamber size (not a typical Belgian proof, but added on export guns?); post-1893 definitive proof for black powder. Someone better versed in Belgian proofs might have something to add date-wise, perhaps from the inspector's mark.
As Madtrapper143 said, it looks off face, i.e. there is a gap between the barrels and standing breech. The gun is proofed for black powder only, and the chamber is likely 2 5/8". It is fair to expect someone has tried modern nitro 2 3/4" shells at some point in its long life, erroneously thinking "I'll only use low-brass or target loads." This has probably led to it being off face. Whether the barrels are damascus steel or false damascus (the pattern is etched on) is impossible to tell from your pictures. Trade guns with false damascus barrels were common, and they were cheaper to make than actual damascus barrels.
Even with black powder loads, I would not risk firing it. It was, when new, a working tool built to the lowest specifications possible. This gun did not live its off-days in a felt-lined oak case in a gunroom, but propped up in a barn somewhere. Add several generations of use and misuse, and the risk of catastrophic breakage increases. It might work fine for a while, with suitable loads, but I wouldn't want to be standing near it the day it fails. Best to enjoy it as a piece of history, one that has brought home many fine dinners.
As to the make, there were endless variations put on these hardware store guns, from spurious company names (like yours) to actual company names, to fake makers' names that sound suspiciously close to actual famous makers, to dupe the unwary (like W. Richards, W. Moore, Purdy, etc etc.). I have never come across a complete listing of such guns' markings, but perhaps someone else has.
Great wall-hanger.
