The hard standing, missing gun mountings, and path worn around the tank indicate it's a presentation tank postwar, or a gate guardian. So I wonder if the colour scheme may be a figment of some park keeper's imagination? It's certainly more in a French style.
The auction website for Monsieur Paperfield shows that he is almost certainly a Belgian (the other postcards for sale) so perhaps it is one of the Franco-Belgian presentation tanks.
I know of no presentation tanks in Belgium except the wrecks rescued and placed in prominent locations at Poelcapelle and Ypres. Of the Mark IV Females presented in France, I believe I can rule out all but the ones in Le Havre and Lille (and the ones I don't know about...)
I might be wrong, but I wonder if it might not be a camo scheme, but variations within paint that is supposed to be the same colour, perhaps because:
A) Parts of the paint had to be retouched, and these bits look darker, the difference being exaggerated by the b&w photography;
B) It was partially repainted and differences in the paint batches have resulted in different reactions to weather conditions, with some parts fading more from sunlight and rain.
In the case above, I'd rather say there was a local artist let off the leash. - However, can somebody please put some light on the one attached? Searchlights, strange guns (20-mm?) and a weird camo. - I've no indication about place and time available.
I believe that somehow the Holt Company of the USA obtained a Mark IV after the war, and this is it. I would also like more details if anyone has them.