regarding the number imprint, it is from the paper backing. it indicates that the film was poorly stored. if this film is stored at room temp. for long periods the backing imprints itself. i managed to eliminate this problem by buying from good dealers that don't have old stock lying around (and by storing it in the fridge once it comes in). it can also happen by leaving the film in the camera for a long time 3-4 days onwards is pushing it.
i'm developing this film in pyrocat hd (metol and sodium hydroxide) at 1:1:200 for 60 min. continuous agitation for the first minute then 5 inv. every 10 min. this film is rather resistant to fogging.
You hit the nail on the head... the film was in my camera for a week and to aggravate matters, my camera was in my boot all the time. Ok, just learnt something :-). Thanks !