The saga continues...
I bring home a GeForce 7300 GT AGP card. It "recommends" a 350W power supply vs my 300W, but I do not have a lot on this machine. I was ready to risk it.
Pop out the old card and it is a f&#@ing PCI-E. Which is good in terms of performance and selection, but was bad as I held in my hands an AGP card. What ticks me off is that I entered my machine's serial number into the HP website and it said that I had an AGP slot. The moral of the story is to conform this with the old mark 1 eyeballs prior to getting the replacement. Lesson learned.
Sooooooo, back to Fry's to get an ATI 4350 512MB card for just under $60 after tax.
Happy ending: it went in and runs detailed terrain and water satisfactorily. And I must concede, it is better with the upgraded graphics.