So...

the owner took the offer of $2600 for the 79 300sd (described under "pre-purchase questions"!)

you guys were so informative and helpful so I have to give you all a big thanks!

as well, am taking the car tomorrow morn to MB Motors in Tarzana, CA (Enrique himself answered the phone) to look over and fix the things suggested by the local MB mechanic (in Hollywood, CA).

am very happy to join the club!