Technical master cylinder ID

Can any one identity this master cylinder? Need to replace

 

Looks like a jeep master cylinder dorman m2796. It bolts on to a 49-51 Mercury. 1 inch bore.


To chop,or not to chop. That is the question.

 

It looks even more like an early 50s chevy truck master cylinder.

http://www.classicindustries.com/product/truck/parts/cx4842.html

 

It is written. "Believe Nothing" I read inside dimension instead of identify.