All the London railway stations :
Underground lines : Piccadilly, Metropolitan
AccessAble Access Guide :
Accessibility friendly : Metropolitan line (A step 277-290mm/ gap 40-60mm). Piccadilly line (B step 127 - 140mm / gap 84 - 104 mm).
There is level access between the street and platforms.
General description :
More comment : See above too. Travelwatch Existing Step-free station in December 2011 (allegedly) - Travelwatch
Inclusive Britain Station Guide