The bike doesn't look anything like any other Colnago that I have ever seen ...but I am not very clued up on 1960s Colnagos.
I notice that the bottom bracket shell is not a Nervex Pro one..and that it appears to be a cast one. This design is fairly common on 60s frames, both in the UK and in France. The top-eyes are very English or French...hardly Italian at all.
The seller has not specified the threading of the bracket so I have sent a query to him asking him what figures are given on the bracket cups. I doubt whether Altig Jnr would have specified anything other than Italian..that's even assuming he did not leave the choice to the builder.
Norris Lockley. ...Settle UK