That's the '85 Caddy Eldorado caliper kit. Master Power, etc., all use it because it simplifies the park brake deal. The calipers are kinda weird, but, you you follow the instructions, they DO work, although I don't know if I'd trust the PB in San Francisco!
I've had this setup on one car for almost 10 years with no problems.
Anything Dr. Diff sells is likely to be excellent, just don't swap to "Green" wheel bearings.
