The Traffic Management Act 2004 introduced the facility for councils to send a postal PCN in cases where the CEO was preparing a PCN, but hadn't yet printed it off to attach to the car, or hand to the driver, who drove off before it could be served. There are probably photos on the Manchester website, but these are not a legal requirement. If it came to adjudication, the adjudicator will decide, using the civil law test of "on the balance of probabilities" whether the offence occurred or not.
You can of course, submit representations (not appeal) to the council who are likely to reject them. YOu can also take them to the adjudicators for a final decision, but the full PCN penalty of £70 will be in play if you do.