The one bike shown belongs to a friend of mine and I believe I also know the owner of the second bike shown. The first is definitely not for sale and if the second one is the bike that I think, it is also not for sale, so this means that the OP is looking for information about a bike that they either do not own or whose provenance is perhaps somewhat murky. I know of at least two people who have attempted to recreate/sell bikes as being 50's De Rosa bikes, so when somebody asks a question like the OP, I become very leery. I did provide the information that the decals on the two bikes shown do not coincide with one another. I can also state that some of the information included in the OP's post is simply incorrect. Ugo claims he left premises in Niguarda much earlier than 1957. I take it that the OP is basing his 1957 date on the replica paint job frames built by De Rosa. The decals for the 1957 replica paint job were based upon a frame that De Rosa had in their factory (it was still there the last time that I was there). The dates of the replica paint jobs were not based upon the dates in which the decal changes took place but rather showed the decals as they were at that particular date. For example, I have a bike that has the same head badge as the 57 replica paint job but a different down tube decal, but teh down tube decal is not the same as the one on the '65 replica paint job.

I am somewhat confused as to how being straighforward and clear about what your intentions are for the use of the information could jeopardize one's chances of purchasing a bike.

Rode my 1953 Marastoni (with original paint, decals and components) on a 40 mile club ride today, will likely ride my 1963 De Rosa (with original paint, decals and components) on another club ride on Tuesday...