Hi Richard,
The wheels are not 25 pdr, but they are artillery. I think these are spider rims off either a limber or gun.
Many WW1 18 pdrs were reused in early WW2 fitted with this style of rim in place of the original wood spoke wheel.
I once saw a childs merry-go-round made from a 40mm Bofor trail... I was too big for a ride
