Sorry.
And I probably overstated the case for De Rosa building some of the early Merckx production (or at least show) bikes. But I think the evidence is increasingly convincing on that score. Hilary Stone has had a few enlightening examples, and the blue one on his wool jersey site is pretty convincing for someone who's looked at a lot of De Rosas (and owned a similar one) - the whole build and details just shout De Rosa to me. I doubt the Merckx setup would have produced something quite that much of a dead ringer, even using frame parts supplied by De Rosa. I'm sure I'm not the only one to think that, but I agree it's not a certainty at this point.