420sel ride height

1988 420sel
Ok, I did a search and there has been a lot of discussion on the w124 but not the 126. So I've been noticing lately that my rear ride height is a little low. I checked and it looks to be about 1.5-2 inches above the rear tires (stock wheels, suspension etc.) and the front looks pretty high -- Maybe 5-6 inches above the wheel.
Could somebody check their cars and tell me the proper front/rear ride height? Also, any ideas on what could be wrong? I'm thinking either differential mount or shocks/springs.

Thanks

Peter
1988 420sel
1988 300e (sold)