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A bit out of date, but this interactive map of step free London is very good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 : Step free access to the Ticket Office and platform 1 (to London) only. This station is therefore not accessible. Footbridge with steps to platform 2 (to Sutton). Nearest step-free station is Mitcham Junction.
General description : See wiki
More comment : National Rail Map & Guide.