Whilst the packet Label says "1945 Contract" ( which means after April 30, 1945, when the Germans in Italy surrendered) it was probably issued later in 1945, as the provisional "Government of the South" took over from the Allied Occupation Forces, and returned Italy to a Civilian Adminsitration; The New Italian Army ( Still "RE", as King Umberto (Humbert) II had assumed the throne in 1944 when Victor Emmanuel II abdicated in 1944, and was continuing as Titular Head of State till a Referendum on the Monarchy etc. could be held., in 1946.).
The Factory (G&M) is unknown to me, probably a metal stamping facility which had the machinery and Tooling Knowledge to make the clips quickly. Italy received in late 1945 and 46, large quantities of SMLE No.1 Mark III* Rifles, and No4 Rifles, to completely re-arm the RE, the Navy and the Airforce. Military service was re-introduced, and the Class of 25 ( 1925) was recalled, irrespective of whether they had already served in either the "Southern Forces" or the RSI... ( the Class of '25 had been called up in the RSI in 1944)
And Italy still had large quantities of Airforce .303 ( 7.7x56R) ammo in stock at peace in '45. This ammo plus the supplies of Mixed British/Commonwealth .303 were used for the training of the "New" forces, in the immediate Post-war years, ( SMI, BPD and GFL made .303 ammo in the 1950s; and until the Bolt actions were eventually replaced by M1 Garands, both US and Beretta/Breda-Made in the early 1950s...SMLEs were still held by the Navy and Airforce, and for recruit training until the late 1960s. The Final SMLEs from the Navy were only sold last year ( mostly to Euro-Arms, Val-Trompia, (Brescia).)
Hence the flush-out of Packets of new .303 clips "Made in Italy".
The packet and contents is a real collector's item (First Contract), and should be kept intact...
Clips are marked on side "GMI " (no date)..from Auction photo...They are MINT. Clip design is "Mark III" ( equal sized side-holes including spring end-hole ).
The Clips are stiffer than British and Commonwealth clips, and require some "stoning" internally with carborundum or Arkansas Stone if one wishes to use them, especially for competition. The parkerisation makes them "high friction".
Very nice Find.
Couldn't find any info on G&M yet.