I found for you an intriguing matter. In the present days archives of Piaggio Aero there is a picture (I enclose it), vaguely captioned 'Simulacro in legno' (wooden mock-up). I asked the engineer in charge of the picture files and he said he was unable to identify the mock-up.
It appear to me definitely designed from ing. Giovanni Pegna and his team. In the past (early thirties) Pegna investigated flying wings and some sort of blended wings. I enclose also a slide depicting three wind tunnel models. On the left we can see partially a version of the P.50; in the middle there is a P.16 (or a variant of it), and on the right, in background, there is what seems to be, for all intents and purposes, a flying wing. Moreover I have vague memories of other Pegna's flying wings or projects with leading edge roots blended with fuselage.
The picture of the mock-up in fact resembles an aircraft that Pegna designed during the period of the autonomous design bureau linked to Reggiane; eventually in 1936 Pegna designed the Caproni Ca.401 as answer to the request from Regia Aeronautica of a Caccia da combattimento bimotore (twin-engined heavy fighter). The program was discontinued when a very embryonic mock-up was built.
The intriguing fact is that the mystery pic comes out of Piaggio Aero archives, leading (in my opinion) to three orders of hypothesis: first, the Piaggio mock-up is a different type from Ca.401 that both the Piaggio historian and I are unable to identify; second, the project is a forerunner of Ca.401 designed during the Piaggio period of ing. Pegna; third, the mock-up is really related to the Ca.401 and for one or another reason is now in the Piaggio collection.
Skybolt, what your opinion is?
Two pictues and a multi-view drawing are from archives of my friend late Sergio Govi (I had the pleasure of working with him for several reasearch about Reggiane) and are published also on the series of Sergio's book for Giorgio Apostolo Editore