Thanks for the cross thread posts - they helped a lot!
Getting back to this now, with floppy available. Made a system erase floppy from HP/CPQ. Ran it, put in Smart start = disk error.
G2 Power on, Compaq Proliant banner, memory and CPU's OK, Smart Array 5i recognizes drives; defined RAID 1. I did get into BIOS utilities with F9. It is set to boot from CD drive. It tries CD, floppy, HD, NIC in that order.
Then I tried to boot SmartStart 5.50, disk error.
I tried to load Windows NT. It starts and I get several screens. It does correctly load the multiprocessor kernel (I added a second CPU, heatsink and VRM), sees IDE, but not the SCSI RAID, or SCSI at all. Asks for insert disk for any other controllers (I no got). Then it says NT cannot continue setup and exits.
I was able to get a Smartstart 3.2 HP original CD to run, until it decided it did not support this machine. My copies of 5.5, downloaded, and others created by associates do not work. I just bought a HP original 5.x on eBay-in route now.