The Old London Underground Company appears in an article by The Urban Times

''Visiting an old bookshop not far from Westminster, a picture caught Chambers’ eye. It showed a map of the London Underground, hanging on the wall in such a way that it revealed a glimpse of another picture beneath it. Moving closer to investigate, he saw on the reverse a map of old London, with original tube routes marked on – and it was this realisation of the discrepancy between old and new, with its implications for the abandoned stations along the way, that sowed the seeds from which the idea was to germinate.''

http://www.theurbn.com/2012/03/londons-underground-space-tube-architecture/