I have an old Argus EF twin lens reflex from about 1947, that belonged to my dad. It uses 620 film which isn't available anymore. I bought a roll of Ilford Delta 400 black and white film in 120. I'm respooling it onto 620 spools. My problem is that, when I advance the film, I don't see any frame numbers. The camera has a little opening in the back, with a red filter and a spring-loaded shutter that you move out of the way while advancing the film. On 620 film (and 120 rolls I've used before) there were frame numbers printed on the backing paper. I rolled and rolled the film, but never saw any frame numbers. Does Ilford 120 not have frame numbers printed on the backing paper? I took the camera into a dark bathroom and opened the camera. The film had advanced over half the roll. I rerolled it back onto the feed spool and taped it so it wouldn't unravel. The camera store here, which is a pretty good one (they handle all the pro equipment here in Cleveland) only had Ilford b & w in single rolls. The had Kodak film but it was all in five-roll "bricks".