Yes Steve Platt: see https://www.ldwa.org.uk/London/W/4606/2017.html

Is the route description available online? I'd be interested in doing this as an "anytime" walk.

Who would have thought that London had so many green spaces? Parks, canals, rivers, disused railway lines. History sites thrown in too: the Gunpowder plot; Charles II, his mistress, his queen, his pelicans; the Peasants’ Revolt; WWII memorials.

On the more practical side, many available toilets too (noted in the RD), often a problem when we pass through civilization. A well thought out route and an excellent route description. Thank you, London Group