1947, Type 73A prototype
Photo: Bolko Rawicz, Source (W1)

After recovering his factory from German occupation, Ettore Bugatti started the production of this relatively-small-engined automobile, that he had designed during the war, and showed it at the 1947, Paris Auto Show.
He died a few weeks later.

It is quite interesting to note that the four cylinder Type 73 engines are really two completely different engines. Type 73 and 73C were 1463cc engines derived from the Type 68 design, with two over-head cams and front mounted supercharger, while Type 73A/73B (slightly larger at 1488cc) was similar to the Royale design, with single over-head cam, added a small blower. Type 73B was developped after Ettore's death.

The Type 73/73C engines, as well as the post-Ettore 73B, had for the very time in a "production" Bugatti, a non-fixed head design (the Type 68 prototype also had that). The fact that Ettore's very last designs were fundamentally different from all his earlier designs is nothing short of a sensation, when you consider his stubborness.
I have been told they regretfully didn't work very well...

I do not know how many Type 73s where built, but at least four different bodies are known, the white streamlined coach body at Schlumpf's (see picture), a simpler coupé, a monoposto (at least two built), and a barchetta body much like Type 57G.