Spoken like a true Alfa fan, but is it a custom bodied Alfa? I would argue it's not. It has an Alfa engine but not a Alfa VIN or chassis. What would a GTZ be worth? To me it's a Bitsa
Alfa engine, plus Alfa Series 2 (105/115) rear -- right down to the solid rear axle. I had a friend who used to say that anything with a solid rear axle is a truck. (Not that I don't like my 115 spider, anyway. ) I will give 'em credit for building a bubble roof Berlinetta that doesn't weigh much more than the spider. The spider version was made by Alfa in the '60s.
It's a stylistic exercise introduced by the Frigerio brothers at the 2014 Villa d'Este elegance concours. Based on the Giulia 1600 chassis/engine, the car isn't homologated because doesn't respect the current road rules (unfortunately).