Just a note on JOhn Siemsen's Legnano on eBay. The right side Campy DO has a small hole above the derailleur mount hole (picture 6). That hole was intended as the stop for the derailleur tensioning spring of the one-pulley Campy Sport. My understanding is that post-1961 Campy dropouts did not have this hole, because the Sport had (finally) been discontued. The boss or elevated surface persisted after that, if memory serves (Disclaimer: this is all anecdotal, but I did get really hyped about the seat bolt fastener when I first say one about 1964. Fortunately, this bike is too small for me).
harvey sachs mcLean va.
I am the seller of this ebay item: mid-1960's Legnano mod. Roma olimpiade with Campagnolo headset. Thanks for looking.
Item #7217614370
--
John Siemsen San Luis Obispo, CA