Katie -
On a lark, I reinstalled the OS on the Intel iMac and now printing works. The 110 showed up in the Printer Setup Utility after rebooting was complete and it ran off a D print just fine. I hope everything holds as it is. For anyone's interest, I did not archive and install, just used upgrade and made sure the HP drivers were checked to be installed.
Thanks for all your help on this - happy holidays
DonB