Apparently, there is just over half an hour of John's 8mm home movies in the Lenono archive from 1967 alone - and around 16 minutes of these are specifically labelled "Weybridge". Andrew Solt's "John Lennon:Imagine" documentary from 1988 utilised a few seconds, to good effect, though one can't help but wonder what else there is.
A rough cut of the above (JL:I) circulates in fairly abysmal quality, but does include a bit more - to wit, above: Lennons Snr/Jnr enjoying interaction with livestock, presumably not on St George's Hill, and below: John engaged in more filming, very likely in the garden at Kenwood, plus furry friend:
Why not get a documentarian in to make something of all this, eh? Answers on a balloon...