I am not convinced by this photo, I am not disputing whether it is Rowntrees or not, but whether it is a genuine Fire Brigade photo. These men all look young all about the same age, apart from the driver, the others don't look old enough to drive!!
If you look at photos of fire brigade members from works brigades and others, there is always a mix of ages and experience, not all the same age as on this photo. There are no photos on line, that I can see, of firemen in white trousers and white shoes. The trousers that are in the picture that Birkbeck found look like waterproof over trousers not tight fitting ones like in this photo. My husband who was a fireman had yellow ones, which would show up white on a photo.
Perhaps this is a photo of an old fire engine about to enter a parade or something. To me, these men (students) don't look like firemen.
Edit: I was writing this as Clearly was posting the school photo.