Hi Ryan,
I am just surmising (because I was RAF and not Army), but -
The parts of the gun that we can see look very clean and shiny. The end of the barrel is a brass ring and it looks polished and the rest of the barrel looks shiny. Same with the wheel hubs.
Three men that I can see are holding rags for cleaning, or polishing. Their whole demeanour suggests that they are taking a break from working, not proudly showing off their gun.
I think that the day was either late Autumn, Winter, or early Spring. The day was bright, but chilly - they are for the most part all buttoned up.
They have the look of a "Defaulters Work Party" - soldiers who have been charged with some minor infringement. Boots not highly polished, being out of step on parade and the like. It is the military way of getting all the general housekeeping work done on a camp. There is always something that needs to be painted, or swept, or polished.
I think that the "two striper", on the right, was the man in charge.
Regards
Chas
