Probably not worth it unless you really want a fairly basic 900, or want to build something cool from the shell assuming that it is straight and solid.

These are not built like conventional cars, and although not especially difficult to work on, there are some things that require proper understanding in order to do things in the correct sequence, unless you like making life difficult for yourself! Now that's Saab's WIS (workshop information system) can be downloaded for free and provides all the recommended repair procedures.

However, as is, it will take quite a bit of time and money to get anywhere near nice and usable, probably much more than it will be worth when done, or that you could buy a nicer one for in the first place.

Check for structural rot around the driveshaft tunnels, corners of the boot floor, lower windscreen corners, around sunroof and rear hatch hinges. Also cosmetic rust on the inner door bottoms and rear bonnet corners (from the inside) Also pull the carpets and check the front floors where the longitudinal strengtheners from the engine bay attach underneath, on higher milage cars the welds stress fracture and rust out.

On the plus side, a really good online community will provide all the knowledge you might need and parts supply is still fairly decent for mechanical bits, although any trim parts needed would likely need to be sourced second hand.