Patrick,
I don't have much depth in knowing compatibility cross-over. Those I listed indicate application. For the price, I'd want to know myself. My suggestion to call Harry Sheets will help. He's got some background and I've been to his place. He's got some inventory. He may even have a bad frame where he's cannibalized or can remove to send you. Sometimes members may have spare frames they're trying to get out of their back yards...
The m/c bolts right up to the frame. There is a plate on the outside that ties the m/c to the brake pedal shaft.
Illustration:
https://walcks4wd.com/master-cylinder-tie-bar-mb-gpw-cj2a-1941-1948_p_2179.htmlHere's some images from Luise' M606 that show the plate:
https://cj3apage.com/Forum/index.php?topic=4362.msg35809#msg35809I'm sure Harry Sheets has those too.
As far as the Saginaw conversion, all I can suggest is review this on the 3B Page - it seems to adress column options:
https://cj3b.info/Tech/SaginawSteering.html