Fred,
I think that you will find that Peer had an arrangement with Victor that they didn't pay him a salary but that he was allowed publishing rights on any material he recorded for them. This explains why so much material was collected and "re-arranged" by performers before being recorded.
The borrowing of tunes and verses with slight differences, adding something here forgettting something there has always been part of the folk process as you are already very much aware. I guess therefore that many performers didn't find it an unusual request and if it meant extra money ???
Should be an interesting programme anyway, I look forward to seeing it.

Hoot