help identify prop valve

The MC doesn't matter -- the PV would have been the same either way. Any prop valve could be used for any disc/drum system, in theory, so long as the threads match the lines -- the Mopar non-adjustable ones (73 and up) are "one size fits all" in terms of proportioning effect. And the adjustable ones (up thru 72) are, well, adjustable.

I'm sorry I can't be more specific, but I've never really seen one out of the car.