I would advice owners of this mod to message me asap

Little backstory of why,
I'm working as a Dev on rust type game and my group joins with other who was doing similar game idea because they had gun models, later I find out these gun models are nearly 1:1 replicas from this mod, when I question the dude who "made" the models he said they were his, then later changed it to "we based on unturned rust mod guns", now he saying he got permission to use them from owners of this mod.
If this is true be aware I am not part of this Dev group no more and that they were intending it to be a pay to play game, and so they would be proferting from your work.

Instead of starting a discussion on the mod, why not get ahold of one of the mod devs (Excluding KikET, he just helped with unity settings) and talk to them about?