Please ignore; I misunderstood T-Mar's post above and got things wrong.
While it pains me to contradict T-Mar, and with the greatest respect, I don't think that the 880 dropout debuted in 1962. There's a catalog that's labeled as 1953 on Velo-Pages.com:
https://www.velo-pages.com/main.php?...geViewsIndex=1
It includes both the 880 ("Tour de France") and 934 ("Competition"), and several "early" derailleurs, but not the Simplex Prestige. Unfortunately the catalog is not explicitly dated, though the "famous riders" page 22 includes only TdF winners from the '40s and very early '50s, and Coppi was dead by 1960. I'm only pointing this out to offer the OP an opinion that the subject bike may be from the '50s after all. I have two British frames that I believe to date from the 1950s that have the 880/881 dropouts (though I also have a French Jeunet from the '70s that does too -- they had a long run).
Last edited by Charles Wahl; 04-13-21 at 06:40 PM.