I drive past the winery every day, just lacking the GPR
For many years I worked alongside a local historian who knew of the tanks. he had lived in Dorking all his life and saw them burried. Sadly he died 30 years ago so no chance of more info.
He had his own maps of all the downed planes and V1's that came down in the area. He took me on a dig once, they were trying to recover the guns from a Heinkel 111 that crashed in Blackbrook, as a kid he had got to the crash site before the home guard got there and recovered the top end of the steering yoke, and discovered that the ball races were marked "made in Birmingham"!