Drum roll...guess what it was...! Watts 009 1/2" on a xray developing machine. It was stuck back in a closet above a counter top with a brass cup and copper drain below it. This made flushing the test cocks a pain.
There's no RP on the building which surprised me.
They paid 99.00
Was a learning curve...I haven't touched a RP in a year or so. Thanks to ARTurf I had a good set of cheat sheets.