This came across my Twitter feed this morning: 1973 BBC footage of an actual pagan fertility ceremony in Yorkshire (follow the link to get the video?):
(And they’re still doing it, and are on Twitter)
Which suggests a BBC film (radio?) crew or local colour journalists as outsider characters. But also: look at the costumes, and the hodge-podge of music they’re using, and the way its been repurposed as a way of threatening donations out of locals. Its obviously changed a lot since its Viking origins - and no doubt Grankirk’s ceremonies have too.