This is not a Colnago built frame. Eddy Merckx licensed his name for use on frames made by many companies (e.g. Falcon, Allegro, et al.). They were in general lower to mid range frames made during the bike boom before, and possibly after (depending on the contract license agreement) Merckx started building bikes under his own company's name. This frame is probably from the very late 70s and possibly the very early 80s due to frame features. The seat post diameter (not listed in specifications, it should be included) will determine the grade of Columbus tubing (if original decal). 27.2mm will be indicative of "SL" tubing, larger frames usually use "SP" tubing with 27.0mm post (both lightweight butted tube sets). If post is 26.8mm or smaller it would indicate a straight gauge non-butted tube set. I believe authentic Merckx bikes were being made by circa late 1980. Earlier top bikes with Merckx' name on them before his retirement were from sponsored companies he rode for (e.g. Colnago, De Rosa) and were special edition models (e.g. Merckx "Molteini Team Orange" Colnago Super) clearly having the company's unique frame detail identifiers; e.g. Colnago "clubs" engravings and cut outs.

(Posted on 1/29/2022). Review by Jesper