In 1969 (The picture has a sign that says 1969) the bikes were built by a Belgian, Marcel Van der Este through the "service de course" of Charles Terryn.
Originally Posted by
Munny
It is a known fact that Charles Terryn was the mecanic of Merckx. It doesn't mean that the bikes were Terryn.
It is also a known fact that Terryn has was not making his frames
Seeing Terryn working on Merckx bikes doesn't mean that these were not made by other frame builders.
If in the previous link, Falcon is next to Kessels, there is a serious jump in quality between them and even within Kessels production, the quality goes from the worst to the best.
If you have pictures of Faema Merckx showing the Terryn caracteristics, I'm interested.