Hi,
Are you having difficulty working out how plan of 1602 fits in to days landscape because land fell into the sea including St. Nicholas Church?
According to Sussex Record Society, there was a survey of 1606 giving info on the Church perhaps worth contacting them or the Record Office.
Would suggest that the plan 1602, contains the field names on each section and may well have a description which goes with it, but not photographed by Record Office.