An image -- rather low quality, but it gives a general idea of what the shield looked like "head-on." It strikes me as being bulky and awkward -- not exactly ideal qualities for a mountain gun component! I think I've seen at least one more variation in appearance.

Cannone da 65/17 with shield (2)

Since we were discussing it elsewhere, I thought I provide this. I believe the image originated from an Italian manual, but don't know for sure. There are plenty of photos around of this mountain gun without its shield, but I think I've only seen 1-2 with the shield mounted. 

Cannone da 65/17 with shield

Close-up of an actually little known Italian plane, the Caproni-Fabrizi F.5 prior a night takeoff from Ciampino Airfield, Rome, 1942. Built by Caproni-Vizzola, at Vizzola Ticino, near the Malpensa airfield, the F.5 was designed by Fabrizio Fabrizi, an officer of the Italian Air Force’s Engineer Corps, as answer to Regia Aeronautica’s requirement for a new monoplane fighter (Program R). After the Fabrizi’s death for flight accident with a Breda 28, the development of F.5 was carried forward by on other Air Force’s engineer, the Lt. Riparbelli. But the project knew some delay and when the prototype flew for first time, 18 February 1939, the Italian Air Ministry had already select the Macchi MC.200. In addition to two prototypes, with cockpit close and sliding canopy, Caproni-Vizzola built only eleven F.5s - The F.5 – metal fuselage and wooden wing, Fiat A74RC38 840-HP radial engine, two Breda-SAFAT 12.7 mm machine guns - with some modification as an open cockpit. This planes was assigned as night fighters to 300th Squadriglia at Ciampino airfield for the Rome’s defence and afterwards, 1942, to 167th Gruppo, always at Ciampino, equipped also with CR.42CN (Caccia Notturna-Night Fighter), without relevant result. On half 1942 the F.5 was phased out. From some sources the F.5 is named also Caproni-Vizzola F.5, but the name Caproni-Fabrizi F.5 is most correct (note the name Fabrizi beyond the engine cowling and ahead the cockpit. Victor Sierra