I have the exact same bike as well. 56cm, full 600 with sante' shifters/derailleurs. Pretty much the same rust and scratches as well! I found mine in a thrift store many years ago. I wasn't riding much at the time and the Wife couldn't understand why I'd want it. No way I could pass on it at the price (wont rub it in, but I "stole" it!). Thank god I didn't pass on it. Ironically, mine IS set up as a fixed gear at the moment. But only because I procured a set of track wheels and wanted to see If I'd like riding one. It's a nice light and tight handling bike, and what I had when I started riding again. Since then, the affliction has set in and my stable has grown. It was being neglected as a road bike. As a FG at least it's being ridden and enjoyed again. Don't worry all the parts are cleaned up and stored nicely for when I return it to the roadie it ought to be after a decent track frame is found(no drewing or re-paint here, thanks!). I've been meaning to add the serial # to the data base but didn't want to post pics there as it's set up now.
SSFG post can be seen here

-Andy