I picked up the same setup as the OP, a Chinese Norinco made in '79-'80 in an ATI Monte Carlo stock from a yard sale for $40. Had a busted Tapco mag so I was able to get seller down on price.
Great shooter but I'm in the same boat, would like to drop mine in an original stock but it's proving to be more expensive than I'd like. I can live without a bayonet but going back to a fixed mag is $50-$75 and stocks seem to start around $100 BUT you need to be aware of what type barrel you have. Pinned, short collar or long collar. Pinned barrel have different stocks from short/long collar barrels. And I think the Yugo stocks are different from the Chinese. So not all SKS stocks are universal. Just more money than I'd like to put back in it.
Forgot to add, there's a guy on Etsy called Lucky Shot that makes aftermarket stocks for a lot of rifles including SKSs. I think he's out of Canada. Has several interesting 'tactical' wood stocks including one that's a close copy of the original stock but has a nice rubber butt pad. Around $110 but is cut for the original fixed mag not the removable Tapco duckbill mags. If I can find a reasonable fixed mag I may go this route.
The Monte Carlo stock is at least pretty solid and a few coats of brown Rustoleum looks better than the black plastic. if you plan to swap the stock I'd recommend reading up on replacing the handguard as it's part of the gas tube and requires knocking out a pin to remove the ferruls/metal thingys holding it in place. I was able to reuse my pin but still ordered some replacements up from ebay if needed. It's not hard but easy to screw up if you don't know how. I replaced mine with a railed one from a Tapco I picked up used off ebay so I could mount a TRS-25 red dot. Not the prettiest setup but it groups 7.62x39 better than any of my AKs at 100 yards.