Judging by the pictures, this looks like a tough one to tackle, but you can do it and you're off to a good start. Imo it's always worth saving a game if YOU are up to the challenge, and Space Shuttle is a worthy classic to save.

As for the playfield, yours looks rough from dry rot. You could beg out by the street corner and still not find someone willing to part with a SS CPR playfield reasonably, but you would find one that someone wants too much for. The hardcoat replacement field that is now being offered for $300 would be an excellent choice, IF your playfield is solid enough.
The other route to take in this case (and the one I would probably pursue) is to post a WTB for a Space Shuttle playfield in any condition, one that would certainly be a better one to start with than yours, and there are sure to be more than a few of them kicking around, now that people have been swapping the CPR's in their game.

Good luck in this pinball adventure.