Looks like a variation of the Master to me. There have been several versions of the Master with names that Colnago for legal reasons had to stop using for one reason or another.
For example the Master my wife rides was briefly known as the Master "Olympic" but Colnago couldn't use that name in the US. Perhaps they couldn't use "Competition" either? In that case yours would be a private import or one of a few before that name was dropped.
Gilco tubing sticker?