IL62 crewing
Not all of the crew on this flight would have been flight crewmembers; there could have been loadmasters, engineers, off duty cabin crew (there being no pax). The standard IL6 crew, I believe, is a captain, FO, FE and Navigator and on international flights, they may also have a radio operator/cockpit translator.
I think one of the reasons for this historically was the policy of full employment; why employ just two pilots (and an FE), if you could squeeze in a few more, but the lack of the technology (and the cockpit of an IL62 needs to be seen to be believed) would also have been a factor.