It certainly makes for a very interesting study, John. As far as dodgy lineages go, I can see no reason whatsoever here to doubt any of Cox's contributors. It seems pretty obvious to me that being able to trace lineages and songs back through a line was very important to these people, and Cox did us a great service by actually asking for the information.

The next step as I would see it is did Cox inspire or was he inspired by any of the other collectors in a similar manner.

You could hazard a decent average date for how far back this goes by using what the current mean span of years for a generation is. It used to be loosely 25 years, but I'm sure some demographer will have worked out a more precise figure for the area and period. Unfortunately the key starting point figure doesn't seem to be present, the singer's age. Sod's law!