Excellent post, Warmtoast!
That photo of the disembarkation area at Southampton brings back distant boyhood memories! In the late 1950s, a friend of my late father was well-connected at Southampton and he invited us for a conducted tour. So, at some early hour with my brother and I dressed up (as one did in those days) in grey flannel suits with short trousers, we set off in the family Mk 1 Zephyr convertible for the long drive from Somerset to Southampton (well, it seemed pretty long - it was about 90 miles on single carriageway roads!).
After arrival at Southampton we were shown some rather sorry-looking flying boats on Southampton Water, then had a fascinating tour of the RMS Queen Mary. I remember being astonished that it actually had a swimming pool. After the Mary, we drove past the Queen Elizabeth in dry dock and went to the Ocean Terminal to watch the arrival and disembarkation of a troop ship - it could even have been the Nevasa! Our host said "Watch this - the sausage machine in action!". A sea of khaki-clad men with kit bags poured down the gangways out of the ship and were rapidly processed before boarding the 'Boat Train', which then chuffed its merry way to London.
Back into the Zephyr; then the long drive home... I'm so glad now that I can just remember those days of ocean steamers, steam trains, lots of military jets....and the last of the flying boats! I think it must have been late 1956 as the troops we'd seen were 'coming home from Suez'.