Thanks, what grounds do you think form a stronger challenge. The fact that there are no markings, or that there are markings that haven't been maintained?
Google maps link shows the parking sign is north of my location, and the parking machine south on the other side of the double yellows. Final image shows markings in 2014 (from google maps), that has since worn away.
There are no road markings anymore (once upon a time there were but they haven't been maintained), and I wasn't parked over the double yellows. I didn't think there would be any restriction here.