[sc_rufctr]

Great car but they are getting on now. I know someone who daily's a convertible MB of similar vintage.
His is pretty reliable but things do go wrong. (mainly electrical)

When I look at old cars with electric windows I always check the doors all the way around and door trims.
A careless DIY owner often leaves the door trims loose and the clips and hardware can be missing.
It's not a big deal to fix but it can tell you a lot about the history of the car.

Also check...

Is the "boot" clean and are the rubber mats OK? (rear trunk)
How does the engine bay look? Dust is OK but an engine coated in crud and oil is not desirable. It's easy enough to fix but again it tells you a lot about the history of the car.
Any service or ownership history?