> it is not much use at dating the photograph
No, no - it IS useful! Thanks to everyone so far - and in advance to anyone else who has a view.
As you may have surmised from the title that has been given to the pic, it has been suggested that the date is 1905. I thought it was later - possibly substantially so. I was thinking at least 1915...
The chappie with the dogcollar, 2nd right, was born 1878, and we think the one on the left is his father b1848, d1930.