When I acquired the Vittorio it had a 600 Arabesque mech fitted. It is a smart upgrade and, Dutchie, fully logical from the ever pragmatic perpective Dutch builders tend to have. While I have dozens of Campag mechs laying around, none didn't come on. I went with a Dura-Ace EX mech with 'hatch plate' design instead - the best Shimano had offer at that time. Better performance and more original than if I would have went with Campag.
I agree, due to the same reason I did change my rear mech on the Jan Janssen from Campagnolo to Shimano 105. Because a Campagnolo 980 could not handle teh 28 tooth of the freewheel.
Nevertheless, just for the picture a campagolo should be preferred to my opinion.
Koga Miyata Gents Racer S1980 (in use by my son)
Giant Peloton Superlite 1998-2002
Gazelle Champion Mondial 1980