I don't remember that either FarNorth. My brother now in his mid 60's and his friends of a similar age and older, never had any problems when using public toilets and changing rooms.
From an article tracing the history of Gay activism
In 1952, The Sunday Pictorial published a series of articles called ‘Evil Men’, taking a clear stand against any future legislation that could one day legalise homosexuality, as there were talks of introducing one at that time. One of their articles sheds light on the perception of homosexuality in British society at that time:
“[…] the chief danger of the perverts is the corrupting influence they have on youth. Most people know there are such things – ‘pansies’ – mincing, effeminate young men who call themselves queers. But simple decent folk regard them as freaks and rarities. […] If homosexuality were tolerated here, Britain would rapidly become decadent” (Sanderson, cited from Buckle, 46).
Not only was the general public influenced by the negative tone of the newspapers, homosexuality began to be defined and understood in these terms by everyone, including homosexuals themselves (Buckle, 47). There were constant associations between homosexuality and paedophilia at this point in time; the public opinion remained largely negative in the 1950s, and continued even until much later
I suppose I am older but that culture remained well into the 1960s and was still in some organisations and schools well into the '70s and 80s so gay teachers kept their sexuality very private.