I'm not sure why you've posted this under 'civil'. All driving offences (whether they be speeding, failing to stop, or whatever) are criminal matters, not civil ones.
However the police (and CPS) have up to 6 months to 'lay information' before a magistrates' court, so they're well within the time limit.
Even so, a 'partial registration' (unless it's accompanied by supporting evidence, such as the company's name on the vehicle) would be insufficient to pass the 'beyond reasonable doubt' test required for a criminal conviction. It's therefore unlikely that the CPS would see any merit in pursuing a prosecution.
Chris