After some additional checking, I believe the entry in Le Unita' Ausiliarie dell'Esercito Italiano nella Guerra di Liberazione is incorrect. The 359º rgt. f. «Calabria» was formed on 1 November 1943 as part of the division and remained with the division until the end of the war. Source is L'Esercito Italian verso il 2000, volume 2, tomo I p.468.
The story told of the soldier that was posted on AHF places the unit in the 8ª Armata area of responsibility (specifically the XXIII Cd'A area). I can't find any unit in that army that comes close to a designation of 355º. The map and discussion indicate that this might have been in the G.a.F. XXV or XXVI settori, but a check of G.a.F. units is a dead end.
Pista! Jeff