I'm a big fan of Osanna, and this their second lp is outstanding. In fact their first and third albums are generally higher regarded than this which is probably true enough, but it's still fantastic.
Originally titled "Preludio, Tema, Variazioni, Canzona" it was'nt called "Milano Calibro 9" until it's vinyl re-release in 1980 when the cover art was changed too.
As far as I can gather, Bacalov wrote most of this, I don't have a cd of it, perhaps the liner notes on it clear this up.
As a side note, it's been speculated that Peter Gabriel got his daft Genesis make-up schtick from Osanna who they toured with in Italy. They look truly hilarious on their lp sleeves.
All this info and more can be found on the very knowledgeable italianprog.com website.