As I remember it from the early-mid 90s the LGW based 747-200s had Traveller in the UD whilst the LHR ones had Club. Perhaps it was a 200/100 series difference, but that is how I seem to remember it. I also recall the cumbersome UD emergency exit. I think you had to pull the slide box across from a locker before opening the door?! Imagine how long that would have taken!