Zagato built a number of prototypes of the Tubolare Zagato.
The first one was Spider which looked already remarkably much like the final version but which was rejected as it was aerodynamically inefficient.

Source: Het Klaverblaadje / SCARB / Rens Biesma 1998

Still with a 1300 cc engine, Consalvo Sanesi driving
Source: Het Klaverblaadje / SCARB

Still with a 1300 cc engine, Consalvo Sanesi driving
Source: Het Klaverblaadje / SCARB

Same as above but now with the hardtop installed
Source: Het Klaverblaadje / SCARB

Same as above but now with the hardtop installed
Source: Het Klaverblaadje / SCARB

Same as above but now with the hardtop installed
Source: Het Klaverblaadje / SCARB
The second one was basically as the TZ would become but still featuring square head lights.
In this shape it was introduced at the Turin Motor Show in November 1962.
Source: Quattroruote