The Mini Comtesse chassis plate caries the French homologation date on it. That is a default date, as it has become an approved French vehicle. European law then means it can be used in Europe, as I understand it (subject to dates of legislation). So many Mini Comtesse are getting dated 1975, despite that they might not actually be a production of that year. Mine (For Sale) is an example of this practice, possibly. Its the first Comtesse to gain British registration, I think.
More will be revealed on the Comtesse topic soon.
Did Willam do the same thing? In which case your answer will be on another car, if you cannot read your plate.
The Crayford I had is no longer here. However it would not really help, as it is not a Lawill/Willam and recorded as its own entity, despite the larger part of the machine being imported. There were enough significant differences that it was classed differently and complied with British rules of the time, not depending on European rulings to create a default registration situation. It would be interesting to know if the insurers treated a Crayford differently to a similar specification Willam.