Heads on Campag vary as well. New style 9 speed and 10 speed have countersunk heads; 8 speed have domed countersunk heads and are longer than 9 speed, and before that there was all sorts.
I've just replaced the screws on a 9 speed mech while I was respacing it for 8 speed and simply used 5mm screws of the right length from my box of bits. The head does not really matter except for aesthetics , especially on the lower jockey where there is nothing to foul and I used button head screws..