if u dont manage to fix your temperature display , contact forum member jamesdean he fixes them. checkout the following thread for more info:
http://www.peachparts.com/shopforum/tech-help/313607-outdoor-temp-display-repair.html
replacing all the fluids and filters sounds like a good idea. the only thing i would add, is to have your ball joints inspected by a reputable MB indy shop, or just replace them if you want peace of mind, cause when a ball joint breaks the car can no longer be driven, even getting it up on a flat-bed is a real pain. example, see post#2:
http://www.peachparts.com/shopforum/diesel-discussion/314231-ball-joint-failure-w124.html
hope you enjoy your new benz