Development Hell may have started it, but I got it from Kristen.
Do a search for "Halloween" plus the year of your birth.
This is what I found.
Sorry -- Kristen has inquired as to the identity of these "fabulous looking chaps," which suggests that Kristen's British boy radar is pretty strong.
Why, Kristen, that's Private Lindsey Duncan and Private Jamie Maitland at the Halloween Party at Buckingham Gate in 1976 -- which is not the year I was born, but it did indeed come up when I did my search.