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not so early as one might guess it at first glance
would think earliest possible date late 1960's
lug pattern Prugnat 62/s
dropouts appear to be neither Campag nor Zeus; two possibles might be Agrati or Cyclo
please post again when you have had opportunity to measure tube diameters and check bottom bracket threading and width
since paint finish pretty much gone you could do some light sanding on underside of bottom bracket shell to verify that possible serial not filled in or filed
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