Perhaps the most important online offering is this link here which gives what is claimed to be the sound of the Mc 72 - a spine-tingling sound. If you've read this far the link is just above. Stop. Go back!
The surviving, record-breaking Mc 72 in the Italian air Force Museum. James Kightly.
And here's a link to the reference in the period issue of Popular Mechanics. For particular - and now odd-seeming - reasons, this magazine never mentioned manufacturer or trade names.
Emphasis on the propellers, but also how little frontal area the aircraft has. James Kightly.
The original team, pilot and aircraft.
The Fiat AS.6 engine:
And joint between the fore and aft halves:
[Aeroplane's monthly Aircrew feature is built around a specially commissioned central illustration by my artist colleague Ian Bott (his website here) while I write and compile it.]