I have a carb that I believe is for the old two ton, however I need some help identifying it for sure. It is a solid brass zenith updraft carb (it is not the type for the 22). It appears the fuel line comes into the bottom of a brass fuel bowl attached to the carb. The top of the bowl is brass, with "ZENITH detroit usa, US Patents dec 29, 08 jun 27, 16 other patents pending" Stamped on the side of the carb is " U5 79123" on one side and "u5" on the other. Please post here or email me at firstname.lastname@example.org if you can help identify what tractor this carb is for. I will try to post pictures soon!