Beautiful bike! Shimano 600 EX Arabesque calipers also pull from the right side and would have been 78-84. Golden Arrow 83-86 had a right and a left pull version. Colnago Super Timeline The rear seat stay cap fluted and stamped suggests 80-81, the Colnago rear dropouts suggest 78-80?, the bottom bracket cable routing suggests 82 on, the stamped chainstay suggests 82. The lack of a crease on the inside of the chainstay is a Mexico visual. All the Supers have the crease. My 82/83 Superissamo has flat, stamped seat stay caps and Campagnolo dropouts. From your pictures It looks as though the right chainstay does not have that flat area at the Colnago stamping. Are they different? I would keep it & ride it but probably never stop trying to figure out it's history. It is special!