FWIW I caught a BA 747 from SIN-LHR in 1977. It should have come from SYD but there was a strike of some sort in Oz so it started at SIN with only about 70 of us pax on board.
So few pax that the purser spoke to each of us and when he found I was an aviation person he asked if I'd like to go and meet the crew (far more normal in those days!) which I did. The Flight Engineer, like me, was ex de Havilland Tech School so we got talking and he complained about how the Pratt-engined 747 we were in couldn't get above FL380 until it had flown all night.
OT but everyone (me included) was then commanded to look out of the windows until someone had spotted the aeroplane from Bucharest they'd been advised was joining the same airway. As we were o/h Zagreb and they'd just jailed controller Gradimir Tasić there was some nervousness, no doubt.