I think a great addition would be the U1 and U3 from Berlin's Underground. They were created in 1902, and is 19.7 kilometers long. They start at Warschauer Straße and drive lifted off the ground for multiple stations (using the same track) before going underground after the legendary 'Gleisdreieck' station. It then goes underground for 3 stations before splitting off behind Wittenbergplatz. From there, the U1 travels further west for 2 stations until it terminates at Uhlandstraße. The U3 travels further south-west for a lot more stations. It leaves the tunnel after Breitenbachplatz but remains at same cut-and-cover level for the rest of the route. It terminates at Krumme Lanke. This route would include 3 different 'kleinprofil' (small stock) trains, which would all be from the 1900's, with as Modern train possible for a add-on. This route would be great because it has a lot of different styles in one place and unlike the Bakerloo Line, you see more of the city because you run above ground in the city itself. Also you might be able to explore the tunnels more because they arent as dark and there's is often more to explore. : ) Would also love a Berlin S-Bahn or ICE route.
