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A bit out of date, but this interactive map of step free London is very good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 :
London Overground (Watford DC Line)
AccessAble Access Guide :
Accessibility friendly : Partial.
General description : See wiki
More comment : Step-free access from station entrance to Platform 2 and between platforms only (TFL) whereas National Rail state differently - Platform 1 (northbound) and ticket office fully accessible.
Platform 2 (southbound) is via footbridge. Whatever!
National Rail Map & Guide,