Hiya,
I can't read your document...perhaps because I only have OpenOffice for "word" documents. But, I get what you're asking and my frame was handy so I made a measurement.
I measure the frame rail width to be 2 inches, and the bracket that is welded to the inner frame rail sticks out (toward the center of the vehicle) by another 3/8 inches.
So, the outer face of the frame rail to the mounting face of the master cylinder bracket is 2.375 inches.
I will add as an aside, the welding was pretty darn sloppy, so it could be your bracket is fine, just original sloppy welds.
Good luck!
Dave