Hi,
I can't give you any pointers as to what the uniform is, but it's definitely not Salvation Army. I would have thought it unlikely they would be found posing with the vicar, too.
I can't help with location either, but if you look at the windows behind the group they are taped up in the style you would expect to see during WWII in anticipation of bombing raids, so I would say it's likely to date from this era.
Having looked closely at the faces, I wonder if they might even be the local Home Guard? Some look a bit old to still be regular soldiers.
Hope that helps, if only by narrowing things down slightly!