Nice plane, but really makes yea wonder why no one is building complete reproductions. It seems all these 1 off restores are pretty much complete rebuilds from the ground up. Seems if they can do that they could build them from scratch and sell them so we all have one in our driveway. 
Consider the Flugwerk 190s and the 262s that were built in Seattle. There are folks who are building them ground up. I think it started with F3Fs. I know that there were some Ki-43s that were going to be done and I believe there is a 109 building bunch trying to start up in Germany. There was a crew doing essentially new build Allision Mustangs too in North Dakota.
The issue becomes provenance. There was enough of the crash landed Spit that went into the rebuild/restoration to still connect it.
You think Furballer vs Land grabber is a never ending argument. Visit any of the warbird sites and talk about when it's a new build vs a restoration. It gets ugly. Funny part with this one is prior to it's debut and flight, the 'it's not a real Spitfire" crowd was very vocal. Then it was seen, and they shut up

Bottom line though is there are plenty of folks making new parts so that outside of the Merlin engine, you could certainly pull enough together to make a brand new Spitfire. Same goes for Mustangs, 109s and other warbirds.