Yeah, if your gauge says you have oil pressure I'd say your sending unit is okay, I had a similar situation with my GL where the oil light never came on. I think we concluded that these cars only used one or the other (either gauge OR light) I'd bet your oil light is lit via some electrical anomaly, Camelwagon's light only came on if he turned his headlights on.
I third the engine wash idea as well, get her as clean as you can then let her idle up to temperature and see if she'll show you the leak, if you can't see anything, you might have to drive it around for a while then check and see if there's any fresh oil on anything.
Oh, and I'd say you need a new resistor pack for the blower motor as well. It's right next to the motor (pass. side foot well) and only has a couple screws holding it in, mine had an obvious crack in one coil, but if you can't see any check it with a ohmeter, if you get a resistance reading then that coil is okay. If any of them read as an open circuit then that's a broken one.