I have some antique firearms that only a couple of places have been able to help with my questions. It's better to call them to establish contact the rep. will give you his personal e~mail to continue with pics, etc. When you have an antique you need a professional opinion.
Go here ---> N.FLAYDERMAN&CO.,INC.
BTW; that's a great piece of western history you have there. Winchester just reissued the 1886 this year for their 200th Anniv. (1810-2010).