From 1st April 2015, Single Lower Limb Amputees with 40% War Disablement Pension or more are entitled to receive War Pensioners Mobility Supplement.
More Information at this link: https://www.gov.uk/government/publications/war-pensioners-mobility-supplement
Please be aware that you need to click on "War Pensioners’ Mobility Supplement change from 1 April 2015" in that link to download the PDF which contains the information and how to claim.