I reinstalled Mac OS 10.2.3 and tried to install OS X Server via the method you described using the "MacOSXServerInstall.mpkg"; however, I got a message stating that OS X Server would not install over the newer version of OS X already installed. I must have a copy of Mac OS X Server 10.2 or...
I tried to install OS 10.2 Server on a G4 single processor 1.0 Ghz machine with OS 10.2.6 already installed. The OS 10.2 Server installer stated that it would not install over a newer version of the OS. I thought I could just boot from the 10.2 server disk and erase the disk with disk utilities...