General: Colnago Frame Identification Help Needed

Hi All,

I've recently purchased a second hand Colnago frame. But I'm not sure if it's a genuine one. I'm totally new with road racers and the seller couldn't tell me much about this frame, he bought it second hand as well. So hopefully there's somebody out there who can identify this 'classic' frame.

Most Colnago frames are full-filled with clover stamps and marks.
Mine has:
- one clover stamp on the down tube.
- text 'colnago' on the drop-outs (but no frame number)
- and some decals (colnago/columbus)
- that's it.

Any info/detail about this frame would help me a lot :)

should be authentic, most probably