On the subject of Colnagos without logos...
Check out these two supposed Colnago Sport models which coincidentally have just turned up on the Bay of Plenty.
A German Sport:
http://cgi.ebay.com.au/Colnago-Vintage- ... 0531112923
A Hungarian Sport:
http://cgi.ebay.com.au/Vintage-Colnago- ... 0747011625
They both have logos prominent in the lugs and seatstay topeyes, but they are very different non "Colnago" logos.
One might suspect, based on these differences, that at least one and probably both are fakes.
This raises an intruiging question though... Why would anyone bother to fake such a low end Colnago?
It's apparent that Colnago outsourced its production of the Sport to other framebuilders back in the day, and you can see the "PRODUCT BY VELOSPORT" text on the Hungarian version. It would be interesting to see if the German frame had a similar inscription showing another manufacturer.
Anyway, I have never seen markings of any sort in the lugs of a Colnago Sport before, but then again, I've never seen a Colnago which I knew came from behind the Iron Curtain before either. There is a good chance that both of these bikes could be genuine "Iron Curtain" Colnagos.
More research is needed. I'm going to contact both sellers and see what I can find out. Stay tuned...