Okay, thanks.
I was hoping the batch number might also be used to identify it.
The computer looks to be a home-built. (Lian-Li case, Supermicro P4DCE MB). In order to get it to boot I had to reset the bios, now it has defaulted tot he lowest multiplier (8) and is booting at 800 mhz. I am pretty sure this motherboard only takes P4s so I know they can run faster.
Thanks again. When I get a chance to open it back up I'll check the underside of one of cpus.