Here are TFL's photos:




Here's an informal representation you can send:
Dear Transport for London,
I challenge liability on the ground that the alleged contravention did not occur. There are cars parked on the footpath throughout this road, and the clear impression created by the layout is that the red route restrictions only apply to the carriageway. While ordinarily double red lines would apply to the whole width of the road, the layout on St Helier's Avenue completely contradicts that principle, and does not appear to be sanctioned by the Traffic Signs Regulations and General Directions 2016.
In truth if there are white bays along a red route, there should not be any double red lines either. If there were no red lines adjacent to the bays, such that red lines appears only where stopping is actually prohibited, it would be clear as day where stopping is or isn't permitted.
As the confusing and unauthorised layout does not adequately convey the effect of The GLA Roads and GLA Side Roads (Merton) Red Route Consolidation Traffic Order 2007, the alleged contravention did not occur because the authority has failed to discharge its duties under regulations 18(1) of The Local Authorities' Traffic Orders (Procedure) (England and Wales) Regulations 1996.
It follows that the PCN must be cancelled.
Yours faithfully,
Send this via
https://tfl.gov.uk/modes/driving/challenge-a-pcn and keep a screenshot of the confirmation page. TFL will undoubtedly send a fob-off rejection, but this lays the groundwork for the tribunal.