Linkert MR4 RACING CARB 1946-195?

The MR4's came with a double or duel verturi often called a bombsite venturi. The MR4 series racing carburetors did not have a choke disc or lever and could be used on several models. This one had this special throttle lever with it when found. The Linkert blueprint showed a K model throttle lever and since it had no choke lever it did not require a K model style air cleaner backing plate, should the type of racing require one. The MR series also did not use the usual main nozzle spring and fuel bowl nut to secure it in place, instead it used a short spring and a threaded plug to secure it in place.