The incredible cover shot has been licensed from photographic artist Jayson Hutchins whose nan Rose Payne owns the photo having inherited it from her friend Betty Derrick. John is wearing the famous Afghan coat he wore to the press launch of Sgt Pepper on 19 May 1967 and is holding a bucket and spade in one hand and four-year-old Julian in the other. It looks as if they have just stepped off the ferry at Sandbanks, a few yards from Mimi's home - perhaps they had just been across the water to Shell Bay to play in the sand?
Intriguingly, the man to left of the cropped image appears to be holding a film camera... could this footage survive somewhere? Was it something official? John appears to be looking directly at the camera, did he know what the film was for?
Do you know the answer? If you can shed any light on the mystery email me here.
In a tidy little footnote to the story, years later Julian Lennon bought the coat back for his personal collection.
The full story - and many others relating to John's visits to Sandbanks - can be found in Yeah Yeah Yeah: The Beatles & Bournemouth which can be ordered at the special price of £14.95, here.
You can order a copy of Dorset magazine from here.