This is an amazing weapon model pack if I may add, but I can't help but wonder something; are these models available for modification or porting?

By that I mean, is one able to port these models for a mod to another game? It might get this pack a bit more highlight outside the System Shock 2 community. Also, it seems like Mercurius hasn't been here in a long time.

Note: I have only considered doing the porting, but I haven't done a thing until I get closure if I am able to or not. Figured I might ask here in case someone in the future feels like doing that too.

I would at least attempt to contact him.

yes. whichever mod is on top will override the one(s) below it.