This is a LONDON UNDERGROUND "O" STOCK ENAMEL NUMBER PLATE, measuring 70mm x 140mm approx.
It comes from 3rd class "T" car number 013075, which was built by Gloucester RC&W Co and entered District Line service on 2 November 1938. It was withdrawn for scrapping by Bird's of Long Marston in October 1972.
The enamel is in good condition with light wear to the edges & fixing holes.