Nice bike. Probably a junior racer from the late 1960s. The crankset is a Campy Sport crank. I like them a lot: have them on three bikes. They are well finished, strong and handsome. They aren't too common, but I didn't think they were worth that much. The ones I've seen have aluminum chain rings that are riveted together. As another poster noted, only the outer ring is bolted to the spider. The front derailleur is probably a Valentino (Gran Sport cages have their bolt on top instead of in front), and the rear was likely changed because the original Valentino rear was too stiff and annoying.The hubs look like Nuovo Tipo small flange, but I can't tell for sure. The QR nuts look like them.
Thanks for posting. I'd like to see more of it!