new master cylinder or rebuild?

GGGGGGGGGGGGGGRRRRRRRRRRRRRRRRRR!!!!!!!!!!!!

Sometimes I hate jobber parts stores. The master shown on the internet is alum,but;this being Canada Lordco still has old cast iron masters in stock,so guess what was sent? Apparently Raybestos is in the process of changing thier old masters to alum.

They wont have any alum in stock until all the cast is gone. Whats wrong with them returning old stock?

Anyways,I dont wanna buy one through the internet. Maybe I'll try Napa. I need to have an alum master in my hands before I pay for it,because now Im nervous about any potential sellers dumping old stock on me.