The entry signs are very clear, so it's puzzling you missed them. I'll bet there are no "marked bays" though. An appeal based on signage could be argued on the basis of there being no repeater signs once the entry signs are passed.
Are there no repeater signs ?
Other equally valid arguments can be developed on the basis of (1) fatal errors in the PCN (2) the TRO establishing the zone being incorrectly drawn up, and (3) failure to consider representations assuming you submit them, rather than paying up straight away.
Your photos of the PCN are no good, we need to see all of the two pages, nice and flat so we can see everything. Appeals have been won many, many, times on fatal errors in PCNs