We know who taped New Orleans, and it was a fan. Not sure about Houston.
I believe all four '77 "official audience tapes" are in circulation, but I don't think they've ever been torrented from known lineage sources.
At some point I'll check our copies and see if any warrant release. I believe ours to be third gen, but they are DATs of the gen in front of them.
Return to the Bombscare is from one of these tapes, but again don't know the source EV2 used or the generation.