No idea if this is allowed, but I just don't want to see this get lost and disappear forever. While digging through some old drives I located a VMware image containing Win2K with the DDK and everything needed to build the original xbox kernel (including all source for both retail, chihiro and dev kit images). Build scripts are there and it builds working bios images that I have tested myself on a retail unit with modchip. I don't want anything for it, it just took me forever to get working and things building and didn't want to let it all go down the history plug hole. The whole lot is quite big. Reply here and will work out where I can safely upload it all. Hope this helps someone!
This would be great to get archived and spread around so iterations can still be done if necessary. Appreciate being willing to upload it for everyone!