That is a classic bike, only a few years after Specialized started making mountain bikes at all. From what I recall, the twisted teeth were normal on Suntour freewheels at the time. It doesn't look like it needs much work, and the parts appear to be original. The thumbshifter looks like it still has plastic shipping film on it! If you don't want it, it can probably be sold for enough to buy a pretty nice bike of the type you do want.