Search london history from Roman times to modern day
A bit out of date, but this interactive map of step free London is very good
All the London railway stations :
Underground lines : National Rail First Capital Connect
AccessAble Access Guide :
Accessibility friendly : No part of station. The Booking Office is accessible from street. The station is inaccessible, but you can buy a ticket! There are 32 steps to platforms.
General description : See wiki
More comment : National Rail Guide & Maps