READERS WHO GREW up before the great digital apocalypse will remember the sheer pleasure of discovering hidden cinematic gems buried in the afternoon-matinée slot on BBC Two. It was a seam of cinematic gold, a mine of neglected celluloid, and if you’re not the kind of person who, on clocking that title — 1964’s Séance On A Wet Afternoon — in the Radio Times, unwraps a Scotch 180, slots it into the VCR and hammers in the VideoPlus+ (ask your dad), then frankly, we probably can’t be friends. …