It broke down so frequently it is difficult to date this negative! However D6100 was new 12/58 and 65924 wdn 11/59.

Francis suggests a likely location is about 1/4 miles south of Brookmans Park Station, where a public footpath used to cross the line. The footpath followed a stream in a valley, which is denoted by the line of trees. He says it doesn't look as tidy these days!