Based on the serial number and Piaggio decal, it should be a 1980 model. Based on the presence of a brazed-on bottle and shifter bosses, my initial reaction was a mid-range, Bianchi Limited but it does say Super on the top tube. Later Limited did come with 600EX but I thought the ones from the very early 1980s were Cyclone equipped.
This is not the typical Japanese contractor for Bianchi. Normally I'd say the tubeset was proably Ishiwata 022, but given the contractor it may be an equivalent Tange set. If you remove the fork, it may be stamped with the tube manufacturers logo and a date code.