Hi everyone
Just read your interesting comments - hopefully, together we can move this research further!
Charlie Mac's (Westminster Ballroom) was located in the basement of 30 Strutton Ground, Westminster. Friends and I visited it regularly on Saturdays and I meet my future husband there in 1967!
It was always packed, there was a big glitter ball hanging from the ceiling, Charlie hosted the evening and, as you say, Mrs Mac stood at the bottom of the stairs (at the left and the cloakroom was on the right). She made sure that everyone was dressed appropriately, before they could enter the hall!
Music included 1960s Pop, Country and Western and Irish favourites. There were also Old Time Waltzes and The Gay Gordons and it was always a great evening!
Hope this helps a little, but I'm sorry that I haven't any photos.