Crystal produced its first fight night format in a basement which they called the Harmony Club. This vid is hard to find. The fights are entertaining, but the setting is almost laughable. The women "fight" / wrestle on one mat which is lain on a concrete floor, there are bricks stacked in one corner and the walls are exposed cement. The audience is vocal but behind the camera. Then they went uptown to the Hellfire Club which was located in NYC. From what I recall, it was an S and M club, but hosted catfights one night per month. Then it was on to the Den. I don't think that the Club and the Den were in the same location, but that's only a guess.
I think DPJ has it right regarding their later fights. Deb and her husband produced them and they reside(d) in Illinois. So, all of the regulars from Mary to Andi to Michelle, etc. would have been from that neck of the woods. An ad in the local tabloid makes sense too. BTW, what was with the Mary interview that you mention? I never heard of. or saw it.
I once posed the Q about finding women to fight on their message board and never really got a straight answer. Perhaps the principals were concerned that I was considering opening a rival operation and didn't want to divulge any trade secrets -- like running an ad. LOL