A well armed truck indeed, and with a body designed to stop the incoming .... not!
The listed use included recon, so maybe the Army had thoughts of all- round self defence during recon missions?? Big, bulky and slow for a recon mission - a jeep would be much better, I should think.
The SMG mount on the roof was supposed to be a universal mount to fit either the TSMG or the (by then) more common OMC. It is listed simply as a 'Mount, SMG' without specifying the type.
Wayne, have you been collecting all the items on the Vehicle Outfit List (VOL) to equip the truck? It will look even more snappy with all the kit aboard.
Mike