I'm fairly sure the men in the photograph are standing on the left hand side of Colston Street, as you go up the hill. This would be in conformity with the map '1955-1971 Post WWII GLOUCESTERSHIRE 1:2,500'.
The site is now occupied by an office block, built in the 1950s I would think. There was a Japanese restaurant called "Budokan" on the ground floor a few years ago, roughly where the entrance to "The Dugout" is.
Confusingly, there was a nightclub called "The Dugout" in the basement of a shop on Park Row, only a few hundred yards away, during the 1970s and 80s.
I think the large billboard sign in the photograph is fixed to the wall of "The Griffon" pub, which is still there although its name may have changed.
As a schoolboy in 1975 I spent the summer holiday working in a shop called "Bryant's" in Trenchard Street ( just around the corner from "The Dugout") which sold and hired out camping equipment.
I don't remember whether the YMCA was there in 1975 I'm afraid, although I know my father stayed there in the late 1940s and early 1950s from time to time, and it was certainly in Colston Street then.
In 1975 parts of this area were very run down indeed, with many of the houses in Lodge Street and Trenchard Street derelict and occupied by squatters.
In adult life, for many years I puffed up Colston Street every weekday morning cycling to work, so thanks for this addition to my knowledge of the history of the area.