First I love the old wood stocks, I only have 3 weapons with the mattel plastic. If I could make them a wood stock I would.
Here are some reads to look at on staining and finishing.
https://www.doublegunshop.com/forums/ubbthreads.php?ubb=showflat&Number=415289https://americanlongrifles.org/forum/index.php?topic=38272.0https://www.doublegunshop.com/forums/ubbthreads.php?ubb=showflat&Number=215https://www.firearmsforum.com/firearms/article/3037https://uplandjournal.ipbhost.com/?act=ST;f=1;t=89564;&#top
Research Crane Creek Gunstock Finish, I am working off old memory, but I believe this was the method developed for the military to stain and finish gunstocks in a hurry. Somewhere I have more note about it, but basically they dunked the stocks in huge vats of stain, dried, then applied linseed oil, boiled linseed oil, same as what is usually called by the initials BLO.
I was taught this finish almost 50 years ago by a gunsmith. The closest equal version is in a print of Frank Whiton's Classic Gunstock Finish listed above.
It was my go to finish for gunstocks and game calls, it is a mix of (1) linseed oil, (2) spar varnish and (3) mineral spirits.
These were the high end gunstock type finishes, a finish that was equal to a Weatherby or any custom gun maker's final product.
I made up 2 mixes, one strong on mineral spirits and the second an equal parts of 1, 2 and 3. My first step to a finish was to wipe everything down with a real damp rag. Let those dry thoroughly, then sand with 500 or 600 grit. The apply my first coat, this is an eyeball guess, but equal parts of 1 and 2, and double on the mineral spirits.
Set it aside on the drying rack and allow 24 hour drying time. 24 hours later, they get another coat of the starter mix, and another 24 hours of drying time. Next day they get another coat of starter mix, but it is applied with using a 600 or 800 grit wet dry sandpaper. And another 24 hours of drying time.
By now I have 3 coats, and the wood is pretty well sealed inside and out. Depending on the type of stock the rest of the finishing varies.
My next step might be as simple as one or 2 coats of 1:1:1 mix of the 3 parts applied with a 1000 grit piece of wet dry sandpaper. But it also might mean 5 or more coats of the final mix. It depends on the wood. Some pieces of wood demand a good deep finish look, others a more muted look. Like a fine gunstock, you get to know when the finish is just right.
This procedure looks like it takes a long time, it does, and it doesn't. Each coat only takes a few minutes, even with the wet sanding.