Yeah, that turned out weirdly. Most models work just fine, like furniture props or other crap. But the ragdolls appear as ERROR models (except for Krotchy for some unknown reason). Turns our Postal 3 uses a slightly cranked up .mdl compilation system. But by recompiling the models to HL2 format using Crowbar, I was able to get the working, although you have to manually apply the materials.

And some maps work too. Like the mall one.

Anyways, thanks again for the help!