Out of curiosity I spent hours looking for that Colnago frame. Concentrating on colors and especially any Colnago frame or Bike with the Campagnolo decal on top bar. I surely did not expect it would take much time but I thought I could beat that trick. I gave up. I think it's about an 82-84, but nothing I could find in an image search on Google has that Campagnolo decal there l. Not an expert or know as much as others, but, I've never failed a search like this before. Certainly, it's not a high-high end for the whole construction and parts, but for that decal it's incredibly hard to find.
...too bad about the corrosion, but it's a popular size. A lot of these get repainted, and if you know how to paint, it's not a lot of masking. The correct decals will cost $40-50. I did one just like that a couple of years ago. Bought just the frame, with some paint and chrome issues, like yours...painted the fork to repair the chrome. The original paint and chrome on these was not top quality anyway (IMO). Which I think is why a lot of them get repainted.
I don't really know about the Campy decal, other than a lot of the detailing was specced by the different importers who sold them here.