Somebody gave me a late 80s Pentax yesterday, barley used. Spent a few hours with it this morning, cleaning the body and the lens glass, bought a new battery and fired up the light meter, and I plan to load it and shoot some pics tomorrow.
It's the K1000 model, looks like this:
It needs a lens cap (according to Wikipedia the battery will drain if no cap, leaves metering 'on'); other than that the only obvious issues are noticeable shutter afterbounces on the slower speeds. We'll see how it looks after a roll goes through.
It did not have a Pentax lens, unfortunately; it came with a Ricoh XR (50mm f2):