Very dark patina stock — what to do

[Ron Scott]

This isn’t a Parker but hoping someone on here could help. The gun was built in the 1880s — it’s in good shape and very serviceable as is. No great collector value. Just wondering if there is a way to bring out the grain and shine up the finish. I have no intention of refinishing it but was thinking that maybe linseed oil cut with turpentine might freshen up the finish. Don’t want to do anything until I get some knowledgeable advice. This picture was taken in bright sun— when you look at in inside it looks almost black.

Thanks in advance.