It's a Breda 35 81mm, developed by the French Brandt mortar of '20 years. It fired standard granades of 3,25 Kg to 4 Km, or heavy ones of 6,9 Kg to 1,5 Km. DVX

Aiming the mortar

One of the assault boats of Xa Mas, the Barchino Esplosivo MTM was a fast explosive motorboat  armed with about 350Kg of explosive charge, that was launched against enemy naval targets (generally cargos but also warships). 
For example, two successes of MTM assaults were the destruction of cruiser York and the heavy damage of destroyer Trombe. DVX

MTM explosive motorboat

Repair photo. Autoblinda 40 and 41 were extensively used by Italian reconnaissance units in the Western Desert and Tunisia. At the end of September 1942 there were 298 Autoblinda 41s in use and more were employed by the colonial police.
