EDIT: OMG, so idiotic... I didn't even look at the dates on this thread... Sorry for resurrecting such a dead post.. =(
Definitely stick with pure Boiled Linseed Oil and Tung Oil to refinish... use the BLO first, as it never dries, let it soak in for a few days in a warm area, and do at least 3 applications of each oil, BLO first, then Tung Oil... the Tung Oil should give your stock a rock hard finish that is difficult to damage... and it will look pretty too.
On the subject of shooters vs. collectors vs. investments... I refinished one of my Yugo SKSs with a very high gloss lacquered finish, because it will see lots of crappy hunting weather, rain, snow, mud, and many other things thrown at it. I took another SKS out of the wood entirely, and that has become my main hunting rifle with a Dragunov Stock, though it's heavy as hell, it is accurate to 1MOA out to 200 yards - which ain't too shabby for an SKS. I have a M91/30 that was stripped clean, and BLO/Tung refinished, because I just wanted it to look original, and I'm looking at 2 K31s on the floor right now that I'm deciding what to do with... Both of these K31s were washed in an automotive parts washer, and reoiled, but are otherwise untouched. They look battle weary, but have no dirt or moisture anywhere in them, so they will remain in that condition forever. =)
All in all, if you want to keep your rifles valuable, leave them alone... leave them in the box... If you want to shoot them, at least clean the bores and the actions, the triggers, and get the cosmoline off the wood so you don't ruin your clothes... If you plan to shoot them regularly, or hunt with them, strip them down, and refinish them with a weatherproof finish, either a LOT of oiling, or a heavy lacquer or varnish. No matter what, never refinish them with water based anything... and ALWAYS wear clothes you can stand to throw away when you are finished with the restoration.
When I refinished my first K31, I restained it with a slightly orange stain, which when finished looks absolutely stunning... I need to go searching for that one now, because that rifle is my baby, and it is currently not in my safe. 0_o