Schnieder seems good but I am stuck for the scale as the barrel looks too slim. Some 75s had similar wheels.
how about this F of W for a near match 105/28

Now I have found a few images of the 105/28 with these wheels. They seem to have been rather rare on the 105/28, and a WW2 update. See these links for info, plans and photos:
http://www.italie1935-45.com/regio-esercito/materiels/item/224-canon-de-105-28
http://www.italie1935-45.com/images/terre/materiels/artillerie/CdA/cannone105-28/29.jpg
http://www.italie1935-45.com/images/terre/materiels/artillerie/CdA/cannone105-28/28.jpg
http://www.italie1935-45.com/images/terre/materiels/artillerie/CdA/cannone105-28/41.jpg

please let us in on the secret ? what gun is it ?