ii had always thought the headsets with printing around the cups were introduced before 1967..
and i am pretty sure i recall seeing an original one for sale from a bike ca. 1963 (i bought the dated brooks saddle from this bike)
it is often debated but i guess the <c> marking on the lower cup to have disappeared around 1970..
i know there has been some discussion on CR where people insisted they only appeared AFTER this date and for a short time. what i've seen isn't really consistent with that.
the rounded crown race had the 1mm lip added to it sometime in the late 70s or early 80s.. i think it had something to do with making the stack height closer to the Super Record headset or perhaps for better brake clearance..
i've pasted some additional info from velostuf.com's headset gallery.. mostly his page deals with earlier parts and does not attempt to precisely date them rather than put them in chronological order.. the last version he gives a date for is ver. 2 ca. 1960, so it might make sense that ver. 4 first came out in the early 60s.. i have not looked through catalogs earlier than no. 15 much.. are they on the internet somewhere ?:
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4th version- 4.5 version and 5th version- cups with lettering in a channel CAMPAGNOLO ITALY BREV. CAMPAGNOLO ITALY BREV. with or without <C> on the bottom cup; (with <C> is earlier) plain hex top nut that has 4 lines interspersed with the lettering on it, (earlier) or no lines, (later); a crown race with a rounded bottom, (earlier), or crown race with a squared bottom; plain stamped toothed washer. The words on the inside of the adjustable cup are slightly different, for example earlier versions will say, "ENGLAND" on one end and "1" x 24tpi" on the other end. Later versions will have an adjustable cup that says inside, " 1" x 24tpi ENGLAND" on one end and "Made in Italy" on the other end. Also, the collar of the pressed races, (the part that goes into the head tube) has lettering on earlier versions, and no lettering on later versions, (thanks J. Westerman and hi.campy).
It is common for some parts to seemingly appear mismatched with other parts in a set. However, it may be no less correct. For instance, if the factory was switching over to new wording on the top nut, they wouldn't necessarily throw away older pressed races with lettering, they would use what was available to make up complete sets.
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