It's hard to tell without seeing details of the frame in close up, i.e. seat tube cluster and bottom bracket shell, but it hasn't got profiled tubing, has a curved fork and has the rear gear cable routed through the top tube. This doesn't tally, as Colnago went to straight forks in 1987/88 but only introduced the internally routed rear gear cable in the early 1990s. The lack of profiled tubing would suggest it's a lower end model.
It's hard to tell without seeing details of the frame in close up, i.e. seat tube cluster and bottom bracket shell, but it hasn't got profiled tubing, has a curved fork and has the rear gear cable routed through the top tube. This doesn't tally, as Colnago went to straight forks in 1987/88 but only introduced the internally routed rear gear cable in the early 1990s. The lack of profiled tubing would suggest it's a lower end model.