Reading again Leonard Cramp's 1966 book "UFOs and Anti-Gravity: Piece for a Jigsaw", it strikes me that round about the end of the 1960's, ridicule of encounters with UFOs started to become the norm. Prior to than period, newspaper reports gave a fair bit of credibility to witnesses and generally reported these events in a straightforward manner in a "this happened, make up your own minds" kind of way.
It would be difficult to imagine nowadays the reportage given to 3 mystery lights observed by the crews of 6 airliners and at least 35 airline passengers: on 24th Feb 1959 (I've avoided using names here, from Cramp's book):
"To enable the passengers to have a better view of the objects, the stewardesses turned out the cabin lights and everyone watched the fantastic 'out of this world' spectacle for the next 40 minutes.
Only one passenger was scared. "I told him", said the Captain, "if there was any danger of attack, I'm sure they would have done it long ago"."
And the USAF goes on the "weather-balloon" the story several days later. Despite the negativity of the military, pilots and flight engineers still seemed happy to be open about these things and the press, recognising their authority, was happy to publish.
It seems to me that the entire era of atmospheric nuclear weapons testing (mostly 1945-63) coincided with a huge variety of UFO reports; Cramp constructs his technical theories from observed behaviours and he has no end of good source material to draw from; the book is stuffed with people's accounts of their experiences. I even had a book, as a child in about 1964, about all things "Space Age" which had a section devoted to UFOs, with a bit about Adamski with his pictures, plus another story about a "cigar" ship, where observers waved to people in the ship and they waved back, along with a photo of a similar craft.
Can you imagine any of that today? We haven't moved forward on this topic in 50 years, we've gone backwards if anything.