Yours has the 722.3 4 speed automatic.
The only MB's in the US with the 5 speed (722.5) transmission were the 129 SL and 140 S-Class with the 104 engine, not the 124 chassis.
Yes, the 124 wagons all have the tailgate closing assist.
There were no "trim level" options on the 124's, the were all the same model, however there were different interior options and option packages. You should be able to have a VMI done and determine what yours was ordered with, or go to the MB website and look at the 15 year model overview and you should be able to figure out what was standard and what on your car was special-ordered equipment. They were all pretty much the same though, especially in 1995 (last year).
Hopefull this answers most of your questions. If you have any specific questions just post it here.