Bob & list- Taxing the memory a bit the late Masi Specials & early Gran Criteriums I have seen & worked on or now own (1970 GC) did not come with a Campagnolo statpost binder bolt. It was a cad plated affair, similar in installed look as seen frequently on French frames. When removed the integral key was not forged in place but consisted of a pin captured in the bolt crown parallel to the bolt shaft to stop rotation.
Had a customer of the shop I worked for (1974) that had a Special and wished to upgrade to the latest, Campagnolo unit, washers were required to keep the bolt from bottoming out prior to providing the needed compression.
At the time, we used washers from a TA seatpost binder.
John Jorgensen Palos Verdes Ca. Where the prize tool box has Campagnolo in & on it.