No a/c and the windows don't go down?
They are great, solid,safe cars. Window regulators are an issue. I'd price the a/c and keep in mind that the evap's do fail on these cars and its a $$$repair. They do need tlc though. For the most part diy friendly. Mercedes of this era were actually engineered with an eye toward eventual repair.
If the clear is failing on one panel it was likely a repaint at some point, although MB's of this era if parked outside a majority of the time can have the clear die everywhere.