Yep; you've got the serial number nailed!

You can still buy Kool Lemon touch up paint from Pete at Hyper-Formance.

When I bought my '71 Kool Lemon P13 it had a mish-mash of components. Somebody had put a Williams steel crank on it, for example, and it had Mafac brakes and a SunTour RD. It was rideable though, so I picked up the Campy crank, a Nouvo Record RD, and other bits at swap meets and off eBay over a period of a few months.

I'd be inclined to look for the Campy bits you need and replace them over time, but Shimano parts will be easier and cheaper to find, and will function just fine.

Post some pix when you can.