Hi Terry,
I looked around a bit and have identified 4 of those medals.
I'll list them out as they are positioned in the last picture, the one with the frame.
Top medal - It must be a "Distintivo per le fatiche di guerra" as described here (Italian only, sorry). I am not 100% sure, but given the Allied Victory Medal to the right, I assume that's it.
Top left - "Ordine di Vittorio Veneto". Details. Awarded to all who had a War Merit Cross and had fought at least 6 months in WWI and were still alive in 1968, when the order was established.
Top right - "Medaglia Interalleata della Vittoria". Details. Awarded to all who had a "Distintivo per le fatiche di guerra".
Bottom left - "Medaglia commemorativa della guerra italo-austriaca 1915-1918". Details (Italian only). Awarded to all who had fought for at least 4 months between May 24th 1915 and November 4th 1918 in Italy, Albania, Siria, Palestine or the Dodecanese.
Bottom right - "Croce al merito di guerra". Details. Awarded after 1968 to all recipients of the "Ordine di Vittorio Veneto" that had served for one year in a war zone or were wounded in action.
Apparently the Order of Vittorio Veneto and the War Merit Cross are closely linked, but I have not been able to establish which is a prerequisite for the other or if they are simply awarded together.
Do you have any idea if he served as an Officer, an NCO or an enlisted soldier? Records for officers are most likely to be found in Rome, by contacting the army's archives, whereas for NCOs and enlisted troops you would be better off contacting the military district closest to where he lived at the time. I have no idea if they keep records from WWI.
As for the unit, might he have fought with the Alpini? That's not really a unit, the Alpini counted slightly less than 80000 men in WWI, but it might help narrow it down a bit. Do you know where he fought?
Hope this helps!