what do you mean by clearly not a traffic sign? anyway its strange - i was parked past the sign. are they saying i was supposed to see it before i parked and then remember it say an hour later when exiting? i honestly didnt see it.
even the other, not nearside sign turned away, when you pull out and turn, you are only head on after u decide to make the turn so unless u look up and to the right at that very moment (which noone would do unless prompted) i stand by the fact that noone would see it.
how strong do you think the case is?
A traffic sign is what is defined in the manual of signs, the TSRGD (Traffic Signs & General Directions 2022).
Whilst an adjudicator must consider that the council have put up a warning, he must also judge the council on whether the signs they have put up are sufficient to convey the restriction. This advance warning is mounted very high up, but a motorist driving slowly along is looking for a parking spot and in all likelihood would not notice the sign.
So it's really up to you, take the double-or-quits gamble at London Tribunals or pay the discount if on offer. I don't think there is a slam-dunk win here, but a reasonable chance of success. In cases like this that revolve around sign adequacy, which is subjective, much depends on the adjudicator you get on the day.