I'm looking for some of the preatorian underground maps as well as some of the weird Farm maps. They seem to be missing from any lists I've ever seen.
The maps for the basic city zones are:
P_City_00_06 -- Underground Nova
P_City_00_07 -- Underground Imperial
P_City_00_08 -- Underground Neutropolis
If that's not what you're looking for, I don't have anything else handy to help with that at the moment.