GWR King 4-6-0 No 6000 King George V passes Princes Risborough with the 11.55am Birkenhead Woodside to Paddington in August 1939.

Richard Pike says "This box's maintenance was covered by the LNER locking fitter based at Hitchin and he gained several boxes of his paperwork. he believes the GW&GC Joint boxes were manned by GWR signalmen but maintained by the LNER, hence the upper quadrant signals. "

Photo: H.K. Harman/Rail Archive Stephenson