I used the cold blueing stuff from a local gun store. Just sanded down a little of the rust and applied it in a few coats. Didn't turn out bad at all, but there wasn't much serious rust, just a little surface stuff.
I don't have a rust problem unless I get it wet, it's just the blueing is starting to look a little ratty.
This SKS definitely saw action somewhere sandy. I'm thinking probably in Kazhakhstan, since the reciever cover was extremely worn on the front edge where the bolt hits it and the stock was FULL of sand when I took it apart.
I'm planning on getting one of those new TAPCO stocks with the SAW pistol grip and M4-style collapsable stock soon. It's got a cheap ATI Dragunov stock on it now.