I wouldn't have done it, if it hadn't been in such rough shape, when I got ahold of it. It had several coats of shellac on it that had been roughly painted on, on top of everything. Wood. Metal. The barrel and bolt. Really nasty mess.
I don't intend to ever sell it, but I like the way it looks now. This would have been the sort of finish it would have come out of the factory with, which was what I was trying for. Clean up and restore to period correct standards, best as possible.
If this thing had come in near-mint I'd have never touched it...
EDIT: Apparently the Russians DID use pine tar, as well as the Finns. The difference is the Finns left it at that, and the Russians applied shellac over the pine-tar. Don't ask me to quote the source, I've forgotten where I learned this, but by referenced accounts this was how it was done.