What a dump that street is !! If you could download the council photos, (if any), it might show the yellow lines even more faded and absent, although your own seem to show them clearly enough. GSV is 2019, so 6 years ago.
However, as I said, don't rush to pay yet; wait and see what the others say. If you submit some reps within the discount period they will re-offer the discount, and you get more time to save the money if it ends up having to be that way.