Xpostfacto worked great for me on a Powermac G3 Beige.

the only tip was to install panther from a 9.2 working OS, as the Powermac is willing to boot from 9.2 until Panther is set and running.(and to change the PRAM to a new one)

Once the first Panther cd install is gone, the PM fires 9.2, Xpostfacto is used to boot Panther (asking for the second cd, and finishing the install)

Xpostfacto will probably work on a Lombard the same way, avoiding to remove the HD.

I had some troubles with Xpostfacto at first (i only had 10.2 on it instead of Mac Os 9)