My family's bike shops sold Falcons and Merckx-Falcons during the 70s. This is a Falcon made Merckx frame we have had since new. The serial number is 16166. Sorry about the poor pictures. The frame is attached to the wall along with a signed photo of Eddy. I met Merckx at a bike show in New York. The lug work on my frame looks like the OPs frame.
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Wow! Serial numbers are the same format and within four of each other... Twins!
You have any more information on that thing?