Hi, I'm looking for a little help IDing my early colnago. The frame has no serial numbers (that I have found) and is outfitted with early 70's NR components. The patent on the rear derailleur is '71 and the brake levers have the round holes in the rear. It also has the old columbus sticker. My guess is '72 but , I am far from an expert on colnago's . Is there a possibility of a serial number on the steerer tube ?
pics can be found here: http://www.flickr.com/photos/8945394@N07/
much appreciation for your time and expertise