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A bit out of date, but this interactive map of step free London is very good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 :
National Rail : ThamesLink
Accessibility friendly : There is step free access to platform 2 (to Sutton) via side gate only. No step-free access to Ticket Office or platform 1 (to London). This is not an accessible station. Nearest step-free station is West Croydon.
General description : See wiki
More comment : National Rail Map & Guide.