I recently bought a repainted Colnago frame. I am trying to determine it's era. It has a fluted downtube, round seat and top tube, there is no rifling inside the seat tube (like you would see with SLX tubing), it has internally routed cable on the top tube, a screw-in cable guide (nothing built in) on the bottom bracket, and horizontal rear drop outs. (I realize this is easier with pictures, and will try to post some.) Are there any Colnago experts/afficionados out there that know the variations among the 80s and 90s vintage frames? Thanks.