Another good place to ask about this is the double gun forum on
www.doublegunshop.com/bbs. Lots of very experienced double restorers and gunsmiths over there and some of them will have specific experience with this maker--I've read threads about them there.
Good luck--I very much hope that you can get this ol' gal shooting again! I saw one in 16x16x.25-20SS that was a work of art.