I remember about the not being married bit
As to the seniority that was still fairly widespread left over form general workplace practices of a previous age
My ex wife started work in a supermarket in 1974 and all married women were senior no matter what service
The unmarried had to call them Mrs."Whoever" and the juniors had to be addressed by their first names. A sort of parents and children situation.
Some women there several years had older married women start and get holiday priority
In fact the unmarried were not allowed to even book holidays until the married had taken all what they wanted
In my work those without children were not allowed to book holidays in school holiday time unless the ones with kids had booked
Made it difficult to get a break at Easter or time off over Christmas.
Going back to the clip.......that was a very BOAC Captain there, a type or aura that would put the fear into you.
I have spoken to ex crew in the past and there seemed to be a preference to the smaller types and a feeling that with the 747 a certain personal touch was lost.
That would probably be true as the 747 moved air travel away from an experience to a means of shifting masses cheaply on a large scale.
In those days passenger dressed up in their Sunday best to travel and wouldn't dream of flying even short domestic in Jeans and plimsolls as it was then.
Air travel was therefore a lot "posher" than it is now and that shows in the advert
BOAC being very "British"

Garry