I'd just stick with the chain keeper tbh. I know it's not as neat but narrow wide won't be enough to always secure your chain without a clutch rear mech, and seeing as you've gone for Campag I imagine you wouldn't be too keen on having a modern mtb rear mech the ruin the look. Assuming all of that, a neat chain catcher, such as the Paul, will work well and not destroy the aesthetic (plus, it's cheaper).
I'd just stick with the chain keeper tbh. I know it's not as neat but narrow wide won't be enough to always secure your chain without a clutch rear mech, and seeing as you've gone for Campag I imagine you wouldn't be too keen on having a modern mtb rear mech the ruin the look. Assuming all of that, a neat chain catcher, such as the Paul, will work well and not destroy the aesthetic (plus, it's cheaper).