Thanks - road must have briefly been narrowed/pavement widened shortly before 2008 (covering the original yellow lines and painting new ones). In 2012 the new pavement covering the road and previous double yellows would have been removed (it's unclear to me if the 2012 photo shows cuts in the road where the extra pavement would have been dug out from, or a crude attempt at indicating that part of the road is now to be a parking bay but these have long since faded. Also the double yellows are not continuous and don't have a perpendicular bar on the kerb side.) This would explain why the furthest double yellows are so faded - they must have been covered by a thin layer of stones and tarmac for that four year period). The fresher yellows were left behind on one side of the junction, and partially burnt away (except around parked cars) on the other side of the junction, position B on earlier schematic).
Hardly surprising everyone ignores them as they are completely pointless, but how should I challenge a non-enforceable but possibly non-rescinded TRO? I took a look at the previous link to Birmingham TROs but there are over a hundred impenetrable documents there and of the ones that looked possibly relevant ie street parking, in only a few cases were any roads listed by name.
On a separate matter, I found at least one old TRO which included photocopies of letters sent to named individuals regarding the illegal parking of their cars many years ago, complete with the car reg and name and address of registered keepers. Surely that's a breach of information governance, and certainly shows that noone reads these documents now!
Anyway, that aside, I would appreciate advice both on challenging this PCN and ensuring that future parking in this spot is not going to risk further ticketing.