You CS looks a lot better than the 1971 CS one of my college chums bought a few months after I bought my Competition from the same company (framebuilder Kawamura, marque American Eagle, then Nishiki). His CS weighed about 35 lbs, with steel cranks, steel rims, and a stovepipe frame; my Competition weighed about 27 lbs, in an era when the best road bike weighed about 23 lbs.
Your experience and my friend's strongly support my assertion that mass-produced Japanese bicycles improved immensely during the 1970s.
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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