Very interesting thread and I'm currently looking at BOAC's 1971 timetable which helps it all make sense - here is the link again.
Index of /ttimages/ba2/ba71
Looking at crewmeal's rosters and Ian Burgess-Barber's post (#11), could someone tell me how much deadheading there was at the time as a proportion of hours flown? I would imagine that not much would be required to & from the USA & Canada but rather more on the Far East & Africa routes looking at the complexity of the schedules. Do you know how it would compare with other long haul carriers? Were crew paid for deadhead sectors the same way as for active sectors or was remuneration based on hours away from base?