Peter,
Please understand the big difference between your situation and mine.
You were aware of the time differences and the various dates.
In my case the dealer either "forgot" to tell me or deliberately failed to tell me. Also, the log book has been falsified as it shows year of manufacture as 2009 NOT 2007, which adds to the deception.
The V5c shows the date of first registration. It does not show the date of manufacture. The old "log book" was the same. The only definitive source of a build date is the Morgan Motor Company build sheet. Do you have this?
You seem to base much of your argument supporting the 2007 date on the dashboard. How do you know that the original owner didn't have the previous layout installed as a special order? Remember, Morgan, especially for regular customers, will make significant changes. I know of one recently manufactured car where the rear number plate mounting fitted, new, is from a 1986 model.
Making accusations about fraudulent alteration of a V5c is something that is best left to a solicitor, and not discussed here.