OP, thanks for posting all of the photos. That is a great example of the flamboyant yellow, which isn't listed in the catalog and looks fantastic in the sun. 23 1/2" frame size perhaps? I suspect those hubs are original since the rims appear to be tubular; no one would replace the original tubular wheels with another set having a lower quality hub. These usually/often came with Campagnolo Nuovo Tipo high flange hubs in the later years, along with the Sugino crankset. That's the original saddle, too, but it isn't very comfortable.

You can check the serial number but I'd say it's a 1972 frame.