A trip to London last week too me to Farringdon & High Holburn station to meet up with some friends.
The old building, as seen in the photo is interesting. You can tell the affluence of the area by the Portland stone main part - a boon for modellers as scribing the stones in plastic sheet would be easy. All the windows are square topped and surrounded by details that would cover up any errant knife work.
Behind, we have London yellow brick. Great for setting the location but there are curved window tops to consider and I've never found a way of doing these without a laser cutter. Not properly flush anyway.
In a nod to history, the words "Parcels Office" can still be seen. A real relic from the era when the underground wasn't just for moving people but a more normal railway system. Apparently there were freight services, including a station in use until the 1920s and the building still stands.
Modelling the underground in these early days would make an interesting prospect as you'd be building something very different from today's "tube".