Hi, guys,
Bearman, you have a good point, but I generally recommend against shooting any very old shotgun, even if the barrels are steel and marked for smokeless powder. You mention part of the reason, the inability to obtain the right length shells for the older chambers, with the result that the shooter often uses 2 3/4" shells, even magnum loads. Another point is that the quality of steel in, say 1910, was not the same as it is today. I may have been too abrupt in mentioning deactivating the gun, even if it has Damascus barrels, but I was considering not only the present owner but future owners.
This is not theory. I recall one case where an old Damascus gun, inherited from a relative, was brought in missing its firing pins. It was evident to me that someone had deliberately removed the pins, and I refused to make new ones. But the boss insisted we do what the customer wanted, so I did, but warned the customer not to shoot it. He assured me he understood and just wanted it complete for looks as a wall hanger. Two weeks later, the gun blew up with a 2 3/4 Magnum load and took part of the owner's hand off. We were not sued, but probably could have been had the guy thought of it. (We did have his written order and there were witnesses to my warning, but I don't know whether we would have won or not.)
If I can see the gun, and check it out carefully, the recommendation might be different, but sight unseen I will take the route of caution. Aside from barrel material, too many of those old guns are flat worn out. I might not deactivate them but most are loose, with badly worn lugs and hinge pins, barrels thinned from decades of cleaning, and large amounts of rust on and into the barrels.
The fact that the question involved a new stock and parts, and an unknown name (we are not talking an AA Parker here) indicated to me that the gun has at least some problems.
I need not point out that I may make recommendations, but they are just that; anyone is free to do as they wish with the old guns.
Jim