Many thanks for all of your replies!
My Grt Grandfather was William Sellick b.1881 in Doynton Glous, then his father Thomas moved up the road to Wick where he was farmer for the remainder of his life. Thomas' brother John inherited the Sellick's farm in Upton Cheyney (Bitton) which their father (also called William) had bought in the 1860's. John died in his early 40's in 1902 and his the farm was sold, the total value of the estate being approx. half a million in today's money.
So apart from my Grt Grandfather, William (with the crooked neck) I have no idea who the others are in the picture, whether they are relatives, friends or work colleagues.
To add to the hunt or shoot debate, I googled hunts in doynton, and found that currently there is a Wick and District Beagles(!) hunt, who hunt hares. So perhaps the picture was of kennels and not stables as I previously thought, and maybe my grt grandfather worked with the dogs or was involved in the hunt.
Thanks,
acceber