mustang II master ?

just put a mustang II master in the poncho- the exit port at the rear is larger than the front- anybody know which one feeds the rear brakes and which one the front

 

Is it a split reservior? Usually the front brakes use the bigger one, which is the back reservior. The rears usually use the front reservior.
I may be totally wrong. And I probably spelled reservior wrong too.
Damn beer