welcome to the dark side (I'm also a diesel owner).

Just like your w126 diesel, rubber suspension components can be an issue. Check out front subframe bushings, front sway bar bushings, engine and transmission mounts, flex disks, etc. as well as the usual mechanical basics like engine and transmission operation, etc.

Also take a look at the convertible top. if it is headed towards replacement time or some of the seals are going then you can be into some additional dollars. The flexible rubber seals that are supposed - note the word "supposed" - to seal between the convertible top and the top horizontal edge of the side windows are prone to rot and the rubber seals up each end of the windshield, which guide the windows in a rubber channel, are also prone to rot. Replacements for those vertical channels on the windshield are $150 each unless you want to play roulette with a poorly made Uro part.

These cars are harder to work on than the w126 simply because there are more parts crammed into a smaller place. Flex disk replacement for example is way more labour intensive simply because of the extra stuff that has to be pulled off to gain access.

Hope this helps ......