Les -
First of all, why are you choosing the 8th century as the last time pagan practices took place? Are you really suggesting that because the Synod of Whitby happened, everyone in all parts of Britain suddenly conformed in their beliefs? It's certainly true that when church going was made obligatory, people went to church, but that's about all you can say with certainty. How do you begin to work out what people over all these years believed in? Of course we all know that these days no one drives without insurance or without a seat belt, because it's illegal to do so ....Yes, right. So it was compulsory to go to church and pay your tithes, and that made every single person a Christian?
Secondly, yes, most of our traditional songs go back no further than the 18th century as far as we can tell. And even from then, we have very few "Christmas" songs. Why are you expecting winter solstice songs to have fared better?
Thirdly - "If people wish to believe they are part of a tradition that goes back a lot further it's none of my business really. If they want to tell us what it is and why they think it is very old then lets have a discussion." Why do you use phrases like "wish to believe"? And what manner of discussion do you think you can contribute to with any degree of knowledge rather than opinion? The family I've been referring to don't need your seal of approval, nor do they have to justify why they think their traditions are very old. The stories and the practices they still have go back for at least five generations. They know (not believe) that it's an old tradition. I mentioned them in this discussion as an illustration that we really don't know the full picture of traditional stories, songs and practices even in this small archipelago. And why would we? What we know of traditional song and story is always dependent on whether a collector has been given the material by the holders of the relevant song or story. In this case, even if a collector had gone to the family to ask it's far from certain anyone would have wanted to tell them anything.
"New" old material surfaces from time to time, just as new archaeological discoveries result in changed views of those historical "facts" you appear to be so fond of.
And fourthly, "The struggles over religious practice , certainly since the Reformation, have been between different versions of Christianity, not some long term attempt to suppress paganism." What evidence do you have for this? It sounds far more like your opinion and interpretation than a matter of fact - and as "paganism" was often represented in terms of witches and covens from the 17th century onwards I think you might find the picture from the past is a lot more complex than your theory.

Anne