They'll work fine as they are on standard Campy-style shifter bosses. They weren't intended to have a decorative fairing, which is what the Shimano "curved washer" really is, between the shifter body and the down tube. Just screw 'em on and enjoy them. Use a good sized flat-bladed screwdriver so that when you snug them the blade doesn't jump out of the fairly wide but quite shallow slot and mar the screw head. That's the only thing I didn't like about those shifters -- they really rock in every other way that counts.