Delta Private Jets/Delta Air Elite was the former charter/fbo of Comair (Comair Jet Express I think) prior to being purchased. They were hq'd in the Comair GO, at least up until the move, not sure where they went when the move happened. They shared a lot of company functions but were separate certs. In the end it doesn't matter as Comair really owns nothing, Delta owns both.
A couple retired Comair guys ended up there, but you had to know the right people it sounded like.
It also sounds like most the time the pilots come with the planes from owners looking to charter out their jet.
I thought I read someplace Dalpa had a grievance against dal using non seniority list pilots or something for the planes.
There was/is little info available it seems like