The name I was trying to dig out of memory banks was...Cornelo.
Here's a quote from another bike-based archive, and was referring to pics of a bike with exactly the same lug cutouts as shown on the "mystery Colnago";
"well that seems to have cleared that up. Its a Dutch house brand Kokke of St Willebrord. Cornelo is still in business you might want to contact them for confirmation." Anybody in the Benelux region familiar with Cornelo? Is there any connection 'tween Cornelo and Colner? Cheers, Alan Goldsworthy SF, CA, USA