Alright, I got the reproduction water valve bracket from Bill Rolik yesterday. It looks like a good piece and fits well. It does line up with three of the holes that were already in my car, so I won't be needing measurements from anyone after all. I know these fasteners aren't correct, they're just for this test fit. Looks like I've got 1 hole from the aftermarket stuff to weld up.

Many thanks to Dwight & Randy for helping!!

Tav