The shop manual from that era says your car came equipped with two 32 PAITA. Of course someone could have changed them out over the years.

Mercedes list the accel pump number for these as #841.

I can't be anymore help than this since most of my stuff from that year is limited to the Mechanical Fuel Injection service.

Note that the specs are a bit different for the front carb than from the rear. Different sized tubes and such.

This might be a good place to look around if you do have the original carbs.

Mercedes-Benz Ponton Solex Type 32 PAITA Carburetor Reconditioning © www.mbzponton.org