As you say Cap'n... A custom in a traditional context is an organic, evolving thing, touched by many hands, over many generations, part of a wider continuity, the corporeal & empirical immediacy of which is of so more importance than any idle speculation on possible origin (or, worse still, meaning). If it's older than living memory, I'd say that's pretty significant; and if it still happens, then surely that's meaning enough.

Unlike traditional songs, such customs can only be transplanted from their traditional context as an imitative approximation of someone's version of the prototype, operating at a significant remove, by whatever degrees of separation, and affected only by whatever agendas comprise the motivation of the participants. I shudder to think what's going through the minds of those hopping Ren-fair re-enactment buffoons in the USA, but saying that, the psycho-socio-cultural context of such cavortings is perhaps worth a look in the light of the current state of world culture, whereby all things, real or imagined, might at least be of some significance to someone.

It has been suggested that the innate cultural conservatism of folkies is altogether at odds with the radical politics that they invariably subscribe to. Not so sure what I think of that myself, but I do feel that the dissemination of tradition is interesting, so long as it is an observable organic phenomenon and not a case of a wholesale 're-imagining' (or 'remake') of something that is alive and well elsewhere.

I started off this thread in a quest for 'authenticity'; I now get the impression that certain parties feel that what they're doing is more authentic than what happens at Abbots Bromley. A grim but not altogether unexpected state of affairs!