As D5500 the TOPS numbered 31018 was the first built example of one of British Railways' more successful first-generation diesel designs that is after the entire class was re-engined from 1964! The early class members were delivered with marker disks rather than having a headcode panel and were dubbed skinheads. Back in 1978 I photographed it working on the North Yorkshire Moors Railway two years after BR had withdrawn it from service in July 1976, see.......
https://www.ontheupfast.com/p/21936chg/25492182204/d5500-freight-goathland-station