Brake Questions - Help

Seems to me you might want to take a look at the fender tag and see how much info is on it. Shop manual will have some basic decoding. Some of the guys here will be helpful, especially if you are putting some effort in on your end. In addition to the imperial club, another great resource is The 1970 Hamtramck Registry Home Page

List of master tech bulletins and filmstrips:
Master Technician Service Conference - Chrysler's Training for Mechanics

here's direct to a picture of the combo valve:
1970 Chrysler Imperial Hydraulic Brake Service Guide from the Master Technicians Service Conference Session 274
1970 gets confusing with all the variations, even though the concepts remain the same. That's why I didn't want to post that earlier when it seemed likely the disks were a factory option.

I looked at the fender tag and it does not list the codes for the brakes. I could not find the build sheet to date in the car.

I see on the Brake Service guide that pre-1970, there is a distribution block, the Texas shaped proportioning valve, and something else, is that other thing the block at the rear axle? Or something else entirely. Thanks for the registry link.