That MC might be okay. Drive the car and see what you think. You'll most likely need a prop valve since otherwise the rear drums will lock up during hard braking.

The problem with brake swaps is that people don't have a lot of "common knowledge" around what works and what doesn't. People kind of know which cam works with which engine and stuff like that but which master cylinder works with which rotor size and how much brake bias there should be and stuff like that isn't common knowledge. So when you start swapping parts around you have to either copy a factory setup, or be prepared to do some R&D.