I realize that this reply is way too late to help you, but perhaps others more currently will have a similar question. Here is my two cents. My Mosin-Nagant is quite the showpiece now, and the effort was fairly minimal.
About the MN.....it came all glopped up with cosmoline which actually seems to have been a great preservative. The gun is in excellent shape (barrel), very little rust, and the nicks and scratches can be cosmetically treated. My great fear was the cosmoline; I had heard lots of stories about how it just keeps leaking out after years of cleaning. Well, having earned a minor in chemistry at the UofArizona I determined that Simple Green, Gasoline, Mineral spirits and other products suggested by friends just wasn't going to be a quick and simple solution to purging that cosmoline barrier coat. So, I went to my secluded stash of diluents and concluded that the chemical structure of MEK, Acetone, Lacquer thinner were likely to be the correct solvents to use on this gun. I quickly discovered that I was right. I doused a rag in lacquer thinner and it easily dissolved the cosmoline totally from the outer surfaces of the rifle....including the stock. Next I poured some MEK (MethylEthylKetone) into the action and magazine. Cosmoline came gushing out like a dam had burst. It dries quickly and I could see that the metal had become decently clean. Next I force sprayed some brake parts cleaner (Walmart) over and through the iron parts to further remove any remaining MEK/cosmoline residue....also thru the barrel. The barrel took about 16 or 20 passes with Hoppe's 9 and Sweet's conditioner, along with some more brake parts cleaner. A bore light showed the bore to have become very clean, only bare metal showed inside, rifling was perfect. Ya just gotta get all that lead out that has been in there so long. So I oiled it up profusely with a few cotton patches soaked in a quality gun oil.
The gun is completely disassembled now, and the parts are shiny clean, no cosmoline is evident. The MEK also lifted the cosmoline out of the pores in the wood, and the total hue lightened up a bit showing the real wood color. Russians used very poor grade lumber back in those years. Sanding it down more and then wiping with a wet, water soaked rag made the good looking grain stand up. I sanded the grain down smooth again and then applied some Red Oak (Min-Wax) stain. After it dried I sprayed three coats of polyurathane gloss over the entire wood stock, let dry for three days, lightly brushed with fine steel wool, cleaned the dust off with mineral spirits, and applied another three coats of polyurathane gloss (hold the spray can about 12-18 inches away from the wood.
It came out beautiful...a nice reddish hue that the Russians seem to be fond of. After letting dry another three days I rubbed it hard with a dry corduroy cloth, and applied an automotive sealer and glaze. That was shiny enough, but when I added my expensive carnauba wax as a finishing coat and rubbed it to a brilliant gloss, it looks like the 'lacquer' is still wet and ready to drip off the wooden stock. The Mosin now hangs proudly in my living room as a tribute to a WWII relic that has been restored to a real showpiece.
During the war the Russians didn't take the time to make the 91/30 look nice...they just threw a coat of varnish over the wood and got them out to the troops ASAP. It doesn't take much to turn it into a beauty. In the near future I will take it apart again and sand down (emory) the black iron and replace it with some bluing by heating the iron and applying the blue. I will also polish the trigger mechanism some. I'm almost afraid to shoot it now -- it looks so good -- but I'm gonna.
Well, that's it. I have had a little experience in refinishing wood products. My main concern was the cosmoline, but the MEK and Lacquer thinner did a thorough and excellent job with no fuss, no muss. I tried gasoline at first...what a joke...!!!
FS