All vehicles should be 100% original and nothing added to them since they were disposed of postwar.
Great intention, but the simple result would be very few vehicles out there for anyone to see! Virtually no German vehicles at all, that is why the restoration of many Axis vehicles are so shrouded in mystery, it's because all they had was a pallet of bits. In my opinion it doesn't really matter, so long as it looks 100% correct and is based on one particular vehicle that is fine. There is a points system (or was) in the UK for cars and IIRC there used to be some guideline about 15% original parts to keep the ID of a warbird.
Forget our hobby for a moment and look at the wider picture. Take classic / vintage cars which dwarfs the MV hobby.
There are only a small number of original 60's sports cars out there, take a TR6 for example: normally new outer panels, new floor, boot floor, bottom of the A and B pillars, sills, front and rear valence, rare to find the original engine and gearbox by now. New hood, carpets, seats, new chrome trim. That's why 'originality' is such a grey area.
If there were to be a regulation which decreed that all none original parts to that vehicle had to be painted pink, most, if not all wartime vehicles would look hilarious
If you are one of the old boys (like Shaun) who got into the game when wartime restoration projects were cheap and you could find a clutch of them on a farm and buy them for scrap money all well and good. Today is a different story, unless you have pots of money you can't get anything like a carrier on a budget of less than £10k for a wreck (five years ago you could, shows the incredible inflation ATM in the MV world). There was a 100% original Carrier owned since the 1960s going in Lincolnshire not long ago. It needed work but it went for £30k!
I'd much rather see a largely reconstructed range wreck, like my Loyd, out and about than to have to read about them in a book alone....that would be sad.
Having said that I respect everyones opinion and if I had the money I wouldn't have started with such a poor project, I'd have brought the 100% original 'Barn find' Loyd from the Farmer down the road and left the Belgian wrecks to the cutting tourch....would it have made me a better man? I'll never know!