Brake Questions - Help

Picture of proportioning valve here: 1967 Chrysler Imperial Disc Brake System From the Master Technicians Service Conference Session 233
along with a good overview of the '67 - '69 disk brakes.

Residual valve shown here: 1967 Chrysler Imperial Dual Hydraulic Brake System from the Master Technicians Service Conference Session 232

1969 Drum Brake info here: Drum Brake Service Highlights (Session 260) from the Master Technician's Service Conference