Isotta Fraschini was an Italian firm in Cavaria best known for making luxury automobiles before World War Two. It entered the arms industry during the war. It made mostly heavy weapons like aircraft cannons, and not small arms, but the chief designer Albertini began working on a submachine gun in 1943. It eventually went into production in late 1944 and early 1945, but only in very small numbers – estimates are 250-500 guns total. These included two distinct models; one using MP40 magazines (as seen here) and one using Beretta 38 magazines.
The most distinctive and interesting element of the Albertini design is the extremely simple construction. It is not just a stamped sheet metal gun, but rather one that can be built almost entirely with a press break and basic punch instead of requiring stamping dies. The parts are riveted together instead of welded, further reducing already-simple production methods.
Thanks to Beretta for giving me access to this example from there reference museum to show to film for you!
“(…)chief designer Albertini began working on a submachine gun(…)”
https://svppbellum.blogspot.com/2020/02/il-mitra-isotta-fraschini-modello.html claims that this was done by 3 people: …It was designed by engineer Giuseppe Albertini, Ezio Robecchi and Livio Segatta, respectively director, designer and head of the experience section of the weapons division of Isotta Fraschini in Cavaria…
“(…)eventually went into production in late 1944 and early 1945, but only in very small numbers(…)”
And then to units: …They armed the Nembo paratroopers department and the Xª MAS. The liberation of Milan and Varese on 25 April 1945 interrupted production. The remaining specimens were taken by local partisan brigades.
“(…)two distinct models(…)”
https://www.traxarm.it/catalogo-scheda.php?id=3354 provides photos of example with following short description RARISSIMA PISTOLA MITRAGLIATRICE DELLA RSI PRODOTTA DALLA ISOTTA FRASCHINI SU PROGETTO DELL´ING. ALBERTINI IN POCHISSIMI ESEMPLARI (250) ALLA FINE DEL 1944 IN DUE VERSIONI, CON SERBATOIO DI MAB E CON QUELLO DI MP.40 (II MODELLO). CONDIZIONI which seems like referencing MP.40 magazine as 2nd model, though I am not sure about that, as I do not know Italiano and thus have to rely at machine translation.