Hi Christian, good to have you here!
More than a few of us have dipped their toes into 3D-design in recent years, so there sure are some models they may have just designed and printed for themselves. If you see a model in a thread you like I’d suggest asking directly where this particular model has come from.
We do have two threads, though, where we collect Chaos Dwarf related STLs either for sale or for free. They will probably never be comprehensive with all the various patreons and free-lance 3D designers out there, but still worthwhile checking them out: