Originally Posted by
Drillium Dude
I also note the Portacatena-drilled rear dropout. I wonder if that would help dating this?
The Portacatena system was introduced in 1977. It is theoretically possible (but unlikely) that Merckx still had these laying around in 1981, as I believe they were only marketed for a couple of years.
Perhaps 1981 was the year it was first purchased...?