Hello Annie
I'm not sure if you know this - but there is an Arthur Helsdown in Hastings Cemetry. He died at sea in 1949 with skipper Harry Muggridge,both middleaged, 49 & 54 respectivey.The lifeboat could not reach them in the fog. There is a short account in Hastings Chronicle (google on this), and the editor, local historian Steve Peak might know more, but perhaps you know all this. The small stone is by the corner of a path below the lower white angel.
Very best wishes for your search
