Well shoot, got the new seal and reinstalled the pump on the NAA. Same leak. It is situated up against the block so I can't see what it going on at the back side but it is still leaking back there. So apparently it was not the O-rings between the pump and the manifold flange.
I will check when I remove it next time to make sure the O-rings stayed put where they needed to be.
I suspect though that the leak is coming from the pump. I rebuilt the entire pump and may have just put it together wrong or a seal did not stay put.
Ugh! I may have to come up with some type of pressure test of the pump to force it to show the leak. : (
Will try now to come up with the rebuild procedure again on that piston pump. I will need that if I take it apart.