Eventually I found it and soon discovered a modern, bright and interactive facility. It was also very full and there were gazillions of children and their parents pulling and bashing everything in site. My grandmother grew up in the Southwark area, and she probably experienced a lot of what I saw between when she was born and when she left the UK in 1919. Surface transport would have been via horsedrawn cabs or carriage or even omnibus, while below ground steam powered trains would have been travelling in tunnels filled with choking smoke.
It is hard to imagine what it must have been like to stand on the footplate on this steam engine while it rattled its way through the tunnels. There is no enclosed cab either, and the crew must have really suffered. Behind them the coaches have an almost Sherlock Holmesian feel about them with their upholstery and woodwork. I have no idea how they ever managed to keep them clean.
Still, compared to the plastic and formica trains of today these were still very opulent. I did find this interesting electric loco that seemed like a very dangerous thing to work on. The carriage behind it was severely lacking in windows, but nevertheless very nice inside.