I was puzzled by what an Eastern Region loco might be doing at London Road and I am pretty certain the station was Leicester Central. The black and white picture has the same style stanchions on the canopy.
The engine in the picture is not Gordon. Gordon the engine in Awdry's books, like all of his creations, is based on a real locomotive and was an A3 Pacific, like Flying Scotsman (a much larger engine than the one in the picture).
The engine in the picture was most likely a B1 or a B17. I can't say for definite because I can't see the wheels and running plate for all the people standing on the platform.
Just thinking ... it might have been 61665 Leicester City. Many of these engines were named after Football League teams, mostly in towns and cities served by the Eastern Region. There is even a Hornby model of 61665.
Interesting post and a good look into Leicester's past.