I feel like a Peeping Tom. Hope Tim doesn't mind. Damn that is pretty. I never saw a buttplate like that before, or even a picture of one.
Mike
I going out on limb here. That looks remarkably like gutta percha. Gutta percha was a tree resin that became popular in the 19th century. They used it much like we use plastics today.
This is case for a daguerreotype.
If the buttplate is gutta percha, it can not be replaced. There are very serious collectors of photographic cases who would pay handsomely for it.
Pete
