Just to put an end on the story:
Everything pointed to the 300CE being a true Sportline, but, due to unexpected financial shifts, I settled instead for a beautiful '92 400E.
If anyone is looking for a '93 300CE, green and tan, in good condition, get in touch with Auto Haus Los Gatos (California) at (408) 370-2655. The owner is asking $22,000.
I had two outside mechanics inspect the car, and both were impressed with its condition.
'92 325is (sold)
'72 250C (sold)
'71 280SE Euro (totalled)