Thanks! That's the first version of the BO (braze-on).
Chuck Schmidt's Campagnolo Timeline says the BO F.der. was first shown in the 1982 catalog. Pro teams might have had it earlier but regular dudes in the US probably didn't get them until after the catalog, so '82 is probably the earliest possible date for your frame, if the BO is original. '83-'84 might be more likely.

And because of the chrome, I'm betting the BO is original.