It’s always interesting to see where old links on the Internet take you. Whilst clicking around, we discovered an old BBC article that spoke about the launch of the London Overground back in 2006, and the new proposed tube map. It seems that at the time the designers planned on having interchange ‘blobs’ all along the whole stretch where Overground trains stopped at the same stations as Bakerloo Line trains.
This had never been considered on parts of the map where two lines ran on the same tracks (e.g. the Metropolitan and Piccadilly lines out to Uxbridge) but it seems that it was considered here. Considered, not finalised because obviously they recognised that it was ugly, and didn’t go with it for the final version.