Skylark, She's a beaut! Looks genuine to me, identical to my first steel Colnago which I bought from Alan van Heerden Cycles in the late 90's. Mine was a steel frame just like this, identical lugs and identical straight fork, which was a Colnago trademark which other manufacturers have now copied. I was priveledged to help-out in Alan's shops on some Saturdays, and spent many hours as a youngster admiring all these frames. The fork & frame lugs look genuine to me, including the rear drop-outs. I could put you in touch with some of Alan's ex-staff members who could possibly scrutinise further. Just a note on the gear 'downshifter' levers - this will give you a chronological clue - when Shimano moved away from STI gear levers (like your Shimano 600 levers pictured) and combined gears into the brake levers, frames of the day dropped the braze-on bosses for the STI levers because they were no longer needed. From this, I would hazard a guess that your bike must be circa late 1980's. I noticed the rear drop-outs on the IMG_4579.JPG do not match your first pictures - perhaps this is not the same frame. I can also offer comment about the guy at Cycle Art - he re-spreayed an old Alpina frame for me back in the 80's and he did such a superb job. He usually did some research and on an expensive imported bike like your Colnago, he would usually only re-spray to a historically accurate spray-job which was originally used by the factory in Italy. Hope this helps you!
