Thanks Steve. I don't think that the drive gear was stuck; I think that the solenoid was engaged. I just came back from the "starter rebuild shop". They pulled it apart and it was totally trashed inside; bar from the commutator missing, braided connector wire "welded" to the communicator, iron filings everywhere, planetary gear locked. Not a pretty picture.
I will check the ignition switch spring and my wife's key chain tonight.
190SL, 230SL 5-speed, 95 E320 Wagon, 01 E320 Wagon, MGB, Boxster 'S', 190SL "Barn Find"