Originally Posted by nolageek
It appears that the first digit of yours are the last digit in the year of production.
date
purchased model S/N
Dec. 1962 Corsa 2F51703
ca. 1981 Campione d'Italia 1M9914
Unknown Selvio S4504D5
Yes, I had considered that possibility, including a reversal of the old Schwinn Month-Year system, such that 2F = 1962 June and 1M = 1981 December, assuming H = August and J = September, ala Schwinn. Unfortunately, other people's Bianchis did not seem to fit this pattern.
Is your Selvio a Japanese Bianchi (BB shell measures 68mm instead of 70mm across, excluding lockring and fixed cup flange)? They would presumably use a different numbering system.
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"Far and away the best prize that life offers is the chance to work hard at work worth doing." --Theodore Roosevelt
Capo: 1959 Modell Campagnolo, S/N 40324; 1960 Sieger (2), S/N 42624, 42597
Carlton: 1962 Franco Suisse, S/N K7911
Peugeot: 1970 UO-8, S/N 0010468
Bianchi: 1982 Campione d'Italia, S/N 1.M9914
Schwinn: 1988 Project KOM-10, S/N F804069