Surely all the recording information that you are trying to gather is available in Tony Russell's amazing Country Music discography. That combined with Charles Wolfe's information should give you anything you wish to know.

Re A.P Carter and the copyright bit, sure he collected and adapted and re-arranged existing songs and if you know anything about Ralph Peer and Southern Music and how he operated you will understand why.
It's all available if you read the books.

Hoot