Cache is not at the published co-ordinates. They are for Dulwich College.
This novelist and screenwriter was born ABCD and died EFGH.
They were born in Chicago and abandoned by their alcoholic father. In order to get the best possible education, they moved to Upper Norwood and were educated at Dulwich College.
Before becoming a writer, they tried unsuccessfully to be a reporter, having written articles or the Daily Express and the Bristol Western Gazette.
Other jobs they held upon returning to the states were stringing tennis rackets and picking fruit.
Cache can be found at N 51 2G.H(G+A)G W000 0(G-E).EG(B/2)
(Checksum for all numbers – 47)