John, I now may have a lead on a used PSB pump or two.  It has been discouraging and I have seriously considered changing to the later one.  My big concern is the mechanical fitup of the various Roosa-specific parts, I thought I could find or calibrate the right pump later.....
Right now it is a Plan 'B' in case I strike out looking for the Head for my pump.

I do appreciate the help I get from you and everybody else.

Thanks,
Larry