Very pretty car, it does look like a plug to make a mould from though as it appears to be internally braced.
Would be an awful lot of work for an amateur builder to put one on the road - it doesn't appear to have any doors, so they'd need fabricating as would a dash prior to making the mould.
I suspect the glass may be a bit of a headache to find too. The front windshield might still be available, but side and rear glass may well have to be made from scratch.
Reading the threads about the seller also suggests that he might not sell it to you anyway if he doesn't like the cut of your jib.
Ultimately it depends on how much you want the car and how big a challenge you are prepared to take on. Would be a stunning car when finished, but that might not be for quite a long time.
If funds are no issue then you could negotiate a price from a specialist custom shop to put it on the road for you, where it might even make it onto one of those chop-shop tv shows.
Good luck and keep us updated on your decision and progress.