You are correct and I am wrong. It is a PDV and PV. I apologize profusely.
KULTULZ, accepted and no problem,

but I
would like to know why you are sooo against adjustable prop valves.

Some history. During the many years I tested brakes, some of the time was spent performing vehicle dynamic balance tests to arrive at desired proportioning results for production. There were many fixed value prop valves used by the factories, differing in "crack points" or knees and psi percentages, based on the vehicle's W/B, weight, CG, tires etc. Adjustable valves
were sometimes used to help the testing, and one valve I still have is a KH that came on some mid-'60s disc/drum Lincolns and/or T-Birds! (Proportioning valves were stand-alone until about 1970) The odds of factory fixed value valves working properly on a custom non-stock brake system is a crap shoot at best. General results will be either too much rear braking, or not enough. The rears should do their fair share without any early wheel slide.
Additionally, combination valves create more plumbing, and are
not very attractive, IMO. Very seldom is the pressure differential switch wired, much less understood. Metering, if included, can make bleeding difficult, and is not necessary.