Fix it up and keep as many original parts as possible. Campagnolo pushrod front derailleurs work well with half-step gearing, such as you have, and your Valentino should be as good as my 1960 Gran Sport. If you can find an early 1960s Campag. Record or Gran Sport, that would be a cool upgrade from that ugly Valentino rear. The frame, paint, and wingnuts are cool.
Disclosure -- my first road bicycle was a low-end 1962 Bianchi with wingnuts and Huret shift.
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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