Hi - this car does not have a hitch, but my other wagon does, however right noe it is tilted up on ramps waiting for me to install a new head. That places the rear too close to the ground to crawl under and make measurements. I will be away for three weeks, but when I get back, and after I get the car back together ( and off the ramps), I will take good measurements and photos. Will a W124 hitch be ok for your W123?

Hope this will help