The dovetail made for the 94 SRC sight can be filled with a piece of cold rolled steel, it doesn't have to be cut and shaped from another rifle bbl necessarily. TIG welding it in place is one way of securing and hiding it. Simply close fitting the piece and swaging (sp?) it into place will do the same thing if done correctly but it takes some skill.
Either way the area around the repair will end up 'in the white' from final fitting and polishing to blend it in right. Then a touch up blue is needed to complete the work. Depending on the degree of orig finish, it may not be a pristine blue that is needed, but something other than a freshly filed and polished surface certainly.
If the repair is right where the original Winchester 95 sight for the SRC goes, the large base of that sight will cover a lot of the repair area.
Repro stocks are available for the 95, but I'm unsure if the carbine style butt is made. You'll have to check around for one of those.
Usually the cresent style rifle butt plate stocks & flat 'shotgun style' butt plate stocks are the types you see made up. That's what I see from Homestead Firearms and Gunville.
Gunville Gunstocks will generally make changes to a pattern like the butt plate style if they have the right specs avail. Email or call them.
Homestead lists the 95SRC rear sight assembly in their Win 95 parts,,but O/O/Stock right now. They are pretty good about getting stuff back in stock though.