You are going to want to get that sorted, but, I don't believe it is impossible to fix what you have, based on what you have posted. A picture or two would be nice.
You will care about value once you get a few quotes for a restock. Several years past Geoffroy quoted 2G for just a buttstock on a Bruchet built R15, in plainish walnut, which, I'm guessing is much more than a 1970s vintage R13 with choke tubes would ever bring.
Good luck with the repair, and let us know what you do and how it turns out.
Best,
Ted
