The throttle body is usually cast on these and it comes off the main float body with two screws underneath. You should be able to find an old carb and just use the throttle body part.
OR
You may be able to weld broken ear back on and then have to make base flat again by setting on sandpaper on good solid flat surface and pushing down firm and moving back and forth w/out rocking to make it flat again. They used to "shave" heads on old bikes in past that way. Or have it machined if cost effective.


G.L. Grumpy's
Old Iron Ranch
Huntington, IN 46750


MM R tractor, Speedex
and Power King tractors