Simon,
I would tend to believe your thoughts also......except for the 2 year thing.........unless it was a herd of craftsmen working on it daily.....and at what cost...........? You had better have some SERIOUSLY COMMITTED workers on this one....... otherwise, you will simply have yet another Goose sitting for another 30 years......and we already can see two of these "kit" cars for sale online at this very moment.......both in FAR better condition (if you can believe everything you read....! 
)) )
You also have the argument of how "original" the car would be after "rebody-ing" the entire car...... This practice is severely frowned upon with US high dollar Mustangs like the Boss 302/429 and Shelbys......but US sheet metal panels typically have date codes stamped in them making it easier to tell if the car is proper when matched up with a "build date" from a Marti report! Later sheet metal dates on everything, than the build date= fraud,.....generally. Gooses have no dates on sheet metal....all hand made.....so could be repaired and passed off as original.........the engine components, brake calipers, windows, and electrical switches usually have dates on them, so they cant be faked easily.....
Nothing I would love better, than to see the owner of this particular project car put together a web page to follow the build down and build up of one of these spectacular cars!!! Take us all on an "it can be done" journey through pictures....... Roger B. has been doing that with a Goose in the UK, progress updates posted in the UK DeT Club's magazine......body is finally in paint! Soon!
Cheers!!!