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

Il Duce talking with a legionary of the Black Shirts M battalion IX Settembre. Adriatic front, august 1944. DVX

Inspection of the Duce

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.