All of this brings to mind a photo in Brett Horton's "Cycling's Golden Age" (p. 186) of Lucien Aimar and Barry Hoban in the 1965 Paris-Tours Classic with the caption reading "... the lack of derailleurs was an attempt (for one year only) to re-create the racing conditions of the 1930s."
Was this the first and only such pro retro race? And perchance is there a need for looking back in pro cycling which seems increasingly more about urine test results and how many watts one produces that the sort of gritty cycling "L'Eroica" celebrates and which it seems pro cyclists have at least some affinity for. I suspect the affinity would last about one stage but if there is a time to get back to basics, this might indeed be it.
Washington DC USA