You can do the alignment check with a stringline, same principle...and fits in your pocket. (although you need something to 'hold' it up) I bought a wrecked k1100, had a bent frame (neck area) and bent triple tree. I don't recall it pulling per se, it must've crabbed down the road. I did replace the frame and triple tree. Its quite a process, but not that bad (get a label machine for wires, tubes etc.) if you like to work on bikes...you will learn it inside and out.
If you can get it for a really cheap price, frames, parts are available. Just know that your looking at a salvage title type bike when done. Guys are café-racering these bikes all over the place, would be fun project...although a 75S is café racer mostly...good luck!