I have finally acquired a new Mac Pro 1,1 to install 10.9 on.
Tiamo at Macrumors has developed a far better method than my Chameleon method. It involves a boot loader he has written.
Thanks to Friso for pointing me to this…
The method was quit simple but required a real Mac. I simply installed 10.9 on a drive in a usb external enclosure attached to my MacBook Air. Replaced the two boot.efi files found at System/Library/CoreServices/boot.efi and usr/standalone/i386/boot.efi and put the drive in the Mac Pro
I have updated to 10.9.1 with software update and it was fine.
10.9.2 required the boot.efi files to be replaced after the update, I keep a 10.7 install on an old drive for this kind of thing.
10.9.3 update from software update went on fine.