Lots of ideas on how to recover the tanks, But no one seems to have thought why are there tanks allegedly still buried at Dorking?, reports at the time imply the "other" tanks were dug/investigated and reburied, but why did not the Tank museum dig the others out too at the time? ..one can only assume they were found to be incomplete hulls/parts, and not worth recovering or inaccessble due to buildings/farm activities etc built over them