I don't think it's a Colnago, it's missing the "stem" from the clover if
that's what it's supposed to be, and the orientation is wrong.
The serial number suggests British to me, generally the Italians used simple numbering
system, the Brits had these obscure codes with letters, numbers, heiroglypics etc.
One way to narrow down the country of origin would be the threading
and the BB width.
Can you post more pictures of the bike?