Mention of Super 8 films in my post below reminds me of one fo my favourite shops in London; The widescreen Centre. It's one of those shops you only get in the Smoke, in that it's incredibly specialist. See also the flute and recorder shops just round the corner from it, between Baker st and Marlebone High st (Dorset st, I think?)The Widescreen Centre sells all things optical that aren't video or 35 mm cameras so, telescopes, 3d cameras and super 8 film stuff. It's a joy! Most of the grainy B&W film you see as reconstructions in tv documentaries (why is that the convention?) are still shot on super 8, mostly bought from this shop.
Hurrah for niche specialist shops!