A few of my colleagues and I know the feeling. For instance, I was the copy editor and first proofreader of scripts for both "Department Store" (stolen and later released as first "Hawks", then "Nighthawks") and "Cryon" (also stolen from the writers but released otherwise fully intact as "Demolition Man"). You won't find the creators' credits anywhere online. I was also the organizer of New York City's PrideFest but, again, after it was stolen by H.O.P., my name quickly disappeared.
The originator and organizer of God's Love We Deliver" was a man named Jay Cancel but a co-worker at New York Presbyterian Hospital took the idea and ran with it, taking all the credit for himself.
My associate producer, Jose Lara, created "Living with Stacy" for television. It was taken from him, reworked and released as "Living with Fran" after successfully cutting him out (he was told that they had to make so many changes to his script that, legally speaking, it really wasn't his anymore so there was no longer any need to credit or pay him).
So many more stories like that one and probably some from people you know who've tried to get their foot in the door.
As for the Hannah broadcasts, it's possible that they still belong to WNYE in New York but I took the name of one of Irwin's writing proteges and, once I find it again, I'll see if he's kept in contact with his family. Maybe I can obtain a copy or two of one of the shows for you.
Still got cardboard Presley, by the way.
