Hi again, first of all, thanks everibody who helped me in this post whith any suggestion, information or related links.
After translating your comments to this friend of mine, good historician and wonderful military man I got this answer (I translate it into Englisg) because merit of identification is yours and I thinh I ought to share it with those who spent their times and knowledges. (Just put the most important)
"....about what you have told me about this photo it´s then more than probably those zeltbahns are captured equipment in Guadalajara battlefield, so probably members of the photo might be from Garibaldi Batallion of XII International Brigade. During that fight in March 1937, whether was awful, so probably the use of that equipment.
Regular italian privates used to wear helmet model M-33 and republican units Adrian helmet, but wool hats were in regimental use in Republican Army, even middle man in photo looks like wearing a employement distinctive for cabo (troop) in the hat in model used in republican army, being not any uniformity identification could may think they belong to Nationalist army. Also the rifle the use look like mosin nagant....."
Thanks in the name of we both.