Sorry that it's taken so long to reply.
Matz - The figures are between 23 and 25mm tall.
Nigel - I keep the in the shed, under the model railway.
I'm considering rebuilding this one. At the moment the base and backgrounds are on mounting card. The Mark II version will be on 2-inch thick foamboard with mounting card background. The foamboard will not only be larger in length but will allow sub-surface detail to be added. Maybe a sunken lane, a bomb crater and slit trenches for use in case of enemy air attack. I will lay it out so that a part hangar can be positioned on the edge so that photos can be taken from the viewpoint of looking out of a hangar.