Today Ivan Berryman linked me to a photo submitted to the IW Heritage Facebook group to see if I could identify.
I was thrilled to see the image was of Ryde Fire Brigade in Brunswick Street (before renamed Station Street). Careful study of the photo gives an idea of when it was posed. The fire station, Ryde's first built-for-purpose station, was first occupied in November 1904 and the engine in the photo on which can be seen Captain Sidney Charles Sapsworth, is the old manual engine purchased in 1852, not the steam-powered Merryweather Gem purchased in October 1908.
So the image below must be between November 1904 and October 1908. Clearly this was a posed photo as there are no horses tethered to the engine so they weren't going anywhere, so my estimate would be that this was taken soon after the new station opened in 1904. To the right of the photo with a length of rope over one shoulder is Henry Frederick Jolliffe, who later became Ryde's Chief Officer and served until his death in 1937.
Later in the same thread a second photo of the same era was submitted, shown lower down below.