I know this is a pretty specific question, but I'm getting desperate. I've looked in Richard Hobbs' book The Carcano, and I've looked online to no end. Does anyone know, or know where I can look for, information about the issuing of rifles? I'm trying to find out what would have been most common for a division fighting in Sicily in 1943. I know the full length 1891 was most common all around with the 38/91 behind it, but by 43 would 38/91s still have been common? Would the 41/91 be replacing it? I know this is the most minute of the minutia, and I apologize.
No panic. Couple of options, this guy below got all manufacturing details, models and years for the different versions of the rifle. Have a look and even drop him an email, he seems well informed.
http://personal.stevens.edu/~gliberat/carcano/
Last resort, get in here, this is the official page of the Italian Army and like most western armies they have a historical section, I suggest you try the 8th link "Museo della Fanteria" this is Infantry Museum. You would be surprised how much these guys are often willing to help. Besides the military history side they are not overwhelmed with work (no offence) so a small challenge is normally welcomed.
http://www.esercito.difesa.it/storia/musei
You seem to be pointing to a specific Division in the Sicilian Front which is a better approach I think, you may ask about the std issued equipment instead of the rifle models themselves. The only last thing I can think about is that you try some of the manufacturers historical records from the 1st link I provided. I only recognize there Beretta as still alive but they should have a good historical archive too, they are the Ferrari in the arms manufacturing in Italy. Not a long shot give it a try.