Campy never had a cottered crank, although sometimes you see chainrings from 3-arm Sport and Gran Sport (neither are cottered) on other manufacturer's cottered cranksets.
In my collection there are Magistroni-made cranks stamped Frejus, Olmo, Legnano, Atala, Fiorelli... there are bound to be others.
Magistroni made chainrings in both steel and aluminum.
Magistroni made raised-letter steel headsets for Frejus, Olmo, Legnano, Atala, and Fiorella, etc., as well as various Magistroni-labelled versions. Typically they have excellent chrome, very good machining of the parrallel surfaces, and good bearing surfaces. Sometimes fit at the opening in the top nut (for the stem) was a bit tight, requiring a little filing, but the threading and the opening seem to be reasonably concentric.
I have found a "Magistroni" company still in existance in Mexico. The name appears on complete bikes. I wonder if Mr. Benotto and the Magistroni family were friends, and moved operations to Mexico with the same idea in mind?