I think with the introduction of 'equality' in the late 70's the all male freighter steward rule was scrapped.
I remember opening a roster for a freighter trip was a bit like opening a Christmas present. You never knew what you were going to get.
There were a group of permanent freighter stewards who, by hook or usually by crook, had got themselves restricted to 'light duties'. As an aside in later days there were a similar group who got themselves restricted to only working the Under Floor Galley on the Tristar - NICE
Some of the trips were very interesting and often included slips in places that a normal flight would not have gone.
I saw everything from baby elephants, dolphins to pallets loaded with gold bars. The gold was a nuisance as getting the trim right meant sitting around for hours. The dolphin was accompanied by a keeper who sat with me on the jump seat and wiped our important guest with some kind of jelly to keep it alive.
Imagine this: we had a small duty free bar on freighters containing half bottles of Scotch, Gin, Brandy and beers for sale to the crew.
One job the cabin crew had was to organise the catering and we would order up special meals such as curries and steak pies for the lads.
My only bad memory of freighters was a long Eastern trip with the same pilots. I had gone out of my way to organise the best meals, research the best watering holes in advance and generally care for them. Nearing the end of the trip was a positioning sector on a non BA airline. The Captain walked up to the check in desk and handed over the tickets 'three First Class and one in Economy'. He very forcefully said.
Still remember it and always thought it would have been nice to say 'three of us have First is there any chance of an upgrade for our cabin crew member?'
That said it was a great experience and much enjoyed.