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A bit out of date, but this interactive map of step free London is very good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 : District, London Overground (North London line)
AccessAble Access Guide :
Accessibility friendly : No entrance/exit. You can change between District line eastbound towards Turnham Green (B step 200mm/gap 113mm), westbound towards Richmond (B step 193mm/ gap 157 mm) and London Overground. No boarding ramps.
Gunnersbury is not accessible to wheelchair users due to stairs between the platform and street level. Level interchange between District line and London Overground is possible. There are 29 steps.
General description : See wiki
More comment : Step-free access between both London Overground platforms only (TFL). National Rail Map & Guide,