David, Attached are a couple butt extension my brother crafted. Watching the process, he always has his moisture meter out checking the material. Depending on whether a permanent extension or removeable for further change in LOP or Pitch, it can be epoxied (not glue) or only screwed in. I've seen and used both and either proceedure results in a functional and solid buttplate. A piece of wood the size of an extension wouldn't have enough length in grain structure to twist and turn like a waterlogged rifle stock. Change in humidity might be enough to swell the wood cells at the juncture. Below: The radiused extension ( on a LC grade #1 20ga.)is partially complete with additional work being a scrimshaw grouse etching in the bone inlays, final carving of the ebony inlays, stock bent to fit, checkering, and hand rubbed finish. Standard extension is on a LC Ideal, not complete.
Good luck. Lots of great guns can be put functionally and aesthetically back in the game. Randy

RMC ... I really like the workmanship in the second photo. But, tell me, how would that look affect value on a older gun? I guess that the short stock makes the gun worth less already. But with a change like that, that breaks away from cobventional thinking, would I be the last owner of that gun? Or would it add value? {I had a Francott Knockabout recheckered in a "fishscale" pattern to give me a better grip in bad weather and when I posted photos online, I was blasted for breaking away from conventionality}. I know of a nice smallbore gun with a short stock and a hideous 2 1/2" ebony extension on it. And to my eye, what your brother did would look great on this gun. And, I don't mind being the last owner of this gun, but I don't like the thought that I "WILL" be the last owner. If you can understand my internal thoughts.
So, what does everyone think ??