Stimpi
Since we have established that you indeed have a laminated single species wood stock. You want to sand it down and remove all the old finish and stain.
Then raise the grain with a wet rag and sand when dry, do those about three times for a very smooth surface, when you wet the stock you will be able to see the final finish color of the wood. All the laminations will show up like wood grain.
I would not use any stain unless there are a few patches that needs to be toned in. Apply three coats to start let it dry and then sand back down to the wood with 600 paper. After that each coat is sanded smooth until all the grain pores are filled.
This will give you a tough and good looking stock. As far as painting a stock I have one too.
Below is an 18oz carbon fiber stock and Balsa Wood with a monocoque design. I build it for my 6ppc bench rest rifle. It will get a better finish yet but I had to find out how well it worked first.
According to the medical write up, the pain and swelling will prevail for several weeks. In three month the other knee will get the same treatment.
I hope I can keep up my will power to get this thing over with. But I don't really have much choice.
Thanks for the good wishes.
Fred M.