http://chevy.oldcarmanualproject.com/1929_54chevyparts/04/293.HTM

The Master Parts Book shows that some of the 1952 1-tons and 1.5 ton trucks used the same master-cylinder.

What type of 1.5 ton truck do you have?

Rockauto.com has a few 1 1/4" bore master cylinders for 1952 1-ton trucks. Maybe someone with a parts book or an interchange book will post information?