that weren't from The parodied, bowdlerised, very fevered imaginings of Dennis Wheatly, Stoker and Mary Shelley via Hammer)

Not that the imaginings of Sir James Frazer (the main source used by the writers of TWM) are any less fevered of course. The paganism of TWM is, like neo-paganism in general, 100% bullshit based on Frazerian fantasy & other highly outdated approaches to folklore.

Quiz time! What legendary Study of Comparative Religion connects The Wicker Man to Apocalyspe Now? And in what way?