SiD the Turtle

Hi guys, We have a bunch of old Compaq desktops that have reached the end of their life and so we're wiping their HDDs, installing Windows XP and then giving them away. The plan was to install Windows XP and use the CD keys stuck to the machines rather than build them using our volume license keys (which obviously is not a very good idea). On the forums here I have seen a few posts that point to how build a script to build the required files to turn a normal install CD into a royalty OEM one, however this requires me to have the original OEM image to extract from. This I don't have! Is there a way to get around this? Thanks, SiD