Colnago used for almost two decades double taper seat stays. In looking at the BB chainstay sockets, the stay ends at the dropouts, the lack of any reinforcement at the chain stay bridge, this is not a Coplnago.
The seat stay top cap treatment and cutout under the top tube on the seat lug point to Cornelo.
DD also made a nice visual comparison of the BB cutout, I think this frame got modified before it got repainted.