Great report !
Reminds me of my first trip to Vietnam in 1989.
Only the BKK-SGN flight was a TG flight, so the culture shock was greater on arrival.
When coming back, the SGN-BKK flight was on VN, an IL-62 (or at least a plane with 4 motors aft, as the IL-62 you describe).
Then the meal was less impressive, as we had only hot Coke and bananas.