Re: LC Smith 10 gauge
If the gun was made in 1897, the wood is "beautiful with no scratches", was "used for geese 20 years ago", and has damascus barrels, you have a problem.
Any gun that was used has wear. This gun, made over 100 years ago, should have patina, or some scratches. The fact that it doesn't, seems to indicate refinishing. There is always the possibility of firing smokeless powder shells in damascus barrels with no ill effects, but not steel shot. Steel shot going through any barrel has the effect of expanding the steel of the barrel, kind of like a snake swallowing an egg. If you look at modern shotgun barrels, you will see the barrel walls are thicker than barrels made over 60 years ago. This is to withstand the abuse steel shot dishes out. Steel going through damascus will interrupt the weld in the barrels, not to mention the solder joining the barrels and ribs together.
Your wife's grandfather, 20 years ago, would certainly have had to use steel shot for geese, as federal regulations required steel shot for waterfowl since the mid 70's, over 30 years ago.
Reading your posts brings up nothing but red flags. Again, my advice would be to take the gun to someone that knows old L. C. Smith guns. Read this carefully, there are lots of guys who are very intelligent and knowledgeable about firearms, but old Smith guns are a speciality.
Good luck on this.