Missing Info on the Model Register

[coh1952]

Very few cars on the model register have a date of leaving factory.
The DVLA record is next to useless - it is the date that the registration mark was first issued (although earlier V5s had a Year of Manufacture note).
I would be grateful for any detailed information so that I can include it in the Model Register.
I am trying to align Chassis number (not always the same as the V5 VIN), registration mark, date of leaving factory, date first on road. Plus any other useful stuff.
Thanks
registrar@midasownersclub.co.uk