There are two possibly major problems with this PCN.
The first is that it is (probably) an illegal demand for money as moving traffic contraventions are subject to the rules set out in the London Local Authorities and Transport for London Act 2003 which includes this limitation
Time to serve is extended if the council requested the keeper details from the DVLA within 14 days of the alleged contravention (that is usually automated) and the DVLA did not supply them 28 days of the alleged contravention.
The second problem, which the council cannot easily swerve the effects of, is that they have sent a Regulation 10 (drive away) PCN instead of a moving traffic PCN.
Please check your postal PCNs for such errors. If the council make an error, just as you may have done by stopping within the yellow box, the council don't get to put their greedy hand into your wallet or purse.
Mr Mustard loves a good council blunder and despite coming up to 10 years of pointing out to the council their mistakes, they just keep on occurring.