Looking at the dates on those NTOs I would do something very quickly.
I would be challenging both with an apologetic ooops, I parked here without realising that I was in a restricted bay because of poor marking and found no PCNs on my return so could not challenge earlier, that the second one was a continuous contravention as the vehicle was not moved and please would they exercise discretion and cancel that one anyway.
Can't guarantee it and they don't say it but many councils nowadays seem to re-offer discount if a Formal Challenge is received within 14 days (beginning with date of service)..... which means today.
Unlikely to get both cancelled, may get one, may get discount offered?
See what others may offer