I'm picking on the GS550E.
This bike was a very cheap project and, although I should ignore it for the time being, I keep delving in and doing different things to it. I already made up a good set of carbs for it, got it running, rebuilt the rear master cylinder because it was dripping etc. and then I decided to check valve clearances. Oh, and also bought a camchain for it because it sounds like it's stretched to buggery.
So rather than strip the engine and, consequently, end up replacing all of the worn or moving parts, I'm treating it as a "repair as necessary" to get a better idea on engine condition — hey, it might yet be useable. If money is no object to you, just rip it apart and make it as new, but if you're doing things on a budget, then this could be ideal for you.