Tom Chambers suggests: The Hobby Horse photograph looks like a Lincolnshire Plough Monday Play double gang, but with 4 Hobby horses. When and where? It appears to have been taken in the summer at the 'Big House' and the House owners are near the centre of the picture. It could be about the 1920s as the 'real' lady in the middle is wearing a cloche hat.
While most of the men are in hobby horses they are nearly all dressed as character parts in the Plough Play, a couple of top hatted doctors, a recruiting sergeant in 1st world war uniform, ladies and bessies and tall hatted hat men. However the drum on the wagon on the left and other instruments could imply that its a concert party using their traditional costumes.