MF30 Carburetor Question?

[Woodworker77]

I have a 1971 Massey Ferguson 30 Industrial tractor with a 4 cylinder Perkins AG4.212 motor. The carburetor that is on it is a zenith and needs to be rebuilt. I am having difficult understanding the model number or finding a rebuild kit for it. The photos are a picture of where the model should be but i cant seem to find any information on it to purchase a rebuild kit. May be a stupid question but i am new here and new to tractors as well so i am experiencing a steel learning curve. Any help is appreciated. Thanks.