Well, I'm now almost afraid to drive it to the shop...but I'm certainly going to take it in. One good thing...I haven't noticed any strange noises upon start-up...but also admit that I haven't had the car long enough to learn it's "normal" sounds. (bought in November and almost immediately stored it until a couple of weeks ago).
Thanks, everyone, for your great advise and counsel (again).
'87 560 SL