Maybe GreatEmerald would know about somone at oldunreal perhaps too who can do it, or himself...as for map specific fixes, these can be made through mutator (which would be linked to a gametype just as that ut base mutator replaces weapons from Unreal) checkreplacement, even adding teleporters to location and other things.
I tried making something, but I am too confused in the Unreal2 code, however some bits from U2deathmatch and single etc would make a coop gametype. And then there could be te fixes through mut...
Also the mutator can support custom maps as well that exist...like the damage mod (found on fileplanet only I think) and others.
Too bad that most of promising projects were cancelled on U2. There was also one by Jaspos, who brought the setting back in Na Pali, but it was discontinued as well...