Marco Pastonesi interviewed Ugo DeRosa in about 1995, for his book Vai che sei solo. During this casual interview, Ugo told stories about how he built frames for Merckx at night for the next days stage, along with discussing his start in the business, and what he had learned over the many years. The interview shows him as humble and hard working, not one who is "Marketing" his product.
Why would Merckx not trust a man to build him a bike (even overnight) who he had known for years, who had been associated with professional athletes since 1958 (Geminiani in '58, then van Looy w/Faema in 1961 and Molteni), had been building frames since 1956 and was his chief mechanic at the time? On page 191 of the Eddy Merckx book is a picture of Eddy, with Ugo holding his bike as he measures the top tube length. Next to them is a bike ready to ride w/the #1 under the top tube, I've always wondered why their measuring up the second bike.
As for delivery of the finished bike, there was the train or a driver with a car to pick-up Ugo and the bike.
The comparison of bicycles to auto racing seems to be justifiable - the reason to make a design/modification overnight is due to a flaw, real or perceived, that was causing problems in handling for your pilot, or simply it's, what Merckx wanted. In pro sports a matter of mm make a difference, and it seems to matter to builders who measure their frames to the mm not cm or 1'". Otherwise we'd all ride 22" top tubes and use a larger/smaller stem.
Brian Van Baush
Evergreen, CO