Hi Bob,
I don't know much about the Kinckerbocker. Did a Google search and really didn't find much. But...
Figure that CAS guns get a pretty good workout each time you go to a match. How old is it and are we talking only black powder in it??? Can you get spare parts?? Don't know. You'll have to find a gunsmith that is willing and knowledgable about these. And it will have to be fixed before you start playing CAS.
There are alot of shotguns on Graybeards as well as over at the SASS classifieds. Some in the $300-400 range. And many have been worked on before the owner now wants to sell.
Coyote Cap (
www.coyotecap.com) is one of the best shotgun gunsmiths in the nation. And there are alot of others, too. I would e-mail Cap and ask him. He worked on my Win 97 and I have an Win 87 on order so I am recommending him highly. He's got more work now than he can get to so he'll give you an honest answer. (he'll tell you the truth even if he was looking for business :wink: )
Best of luck and keep us up-dated,
ÇR