One new EPC brand .700 bore master cylinder, part number 30-1218-A. 

One port is 3/8 x 24 and the second port is 7/16 x 20

 

This fits:

Massey Ferguson Tractors;  200, 500 and 600 series

Massey Ferguson Combine 40

Massey Ferguson Industrial 30E, 40, 40E and 50E