GSV isn't much help.
From what I can see, it's a Restricted Parking Zone, hence no yellow lines anywhere. But this is not the issue.
In order for the contravention to hold, you had to be parked within a marked parking place. The sign is not pertinent at this stage. The order is:
Road marking, then
Traffic sign.
Within a RPZ, no road marking = no contravention of this type.
OP, where were you parked? The PCN gives 'OP5', is this a reference to a property number or what?
The aerial view suggests that every length of street has a marking where one is required e.g. bus stop, zebra crossing, parking place etc. The only lengths not marked are dropped footways(vehicle access and pedestrian) and the configuration of the footway slabs adjacent to your car suggests this is where you were parked. If so, this is a 24/7 contravention. If you were(in order to avoid marked bays) then don't repeat, you could be towed away.
More info pl.