I'd redo the entire stock. When I first left the service, I worked part time for a gunshop, and they would regularly get milsurp rifles from Europe, that had been sitting in large depots, and were rubbed down every six months or once a year, probably with motor oil...just to keep them from rusting, etc.
So we'd redo the stocks. We'd remove all of the metal. IF for some reason the piece had been used for parades, and they had sprayed on some sort of shiny "lacquer" coating, we'd strip that off first. THEN we'd submerge the stocks in hot water for 24 hours....especially the ugly oiled stocks. To that hot water we would add a small amount of detergent. This would pull a massive amount of oil out of the oiled stocks. After 24 hours we'd remove the now de-oiled and water soaked stocks, and rinse them. Then we'd hang them up for two days to air dry. At that point they were ready for further work.
Dent's would be steamed out with wet terry cloth and steam-irons. Then the stock would be sanded a bit, then stained with Fiebing's brand leather dye, in a brown pretty close to what the rifle may have had when it left the factory. THEN...we'd use 4-0 steel wool, it's like steel cotton, and rub in a linseed oil or tung oil finish. The oiling and drying took a couple of weeks as it was a bunch of coats. At that point the metal was checked and it was thoroughly cleaned, the bore got a deep copper-removal-cleaning, and the rifle was reassembled. We didn't sell them as "mint" or anything close, but we did get a good price and the customers were quite happy. The stocks really looked good, even IF I say so, myself.
The point is, I am betting if you simply stripped your stock, soaked it, steamed out dents if needed, then after two days drying you sanded, stained, and applied a new finish....I think the wood would return to what was needed. If fifty year old stocks left in government depots can bounce back, the stock from over the mantle can too and probably more easily.
You're thinking of replacing the stock anyway, so why not give it a try?
LD