^^No doubt but that entire generation of racers generally rode frames that were tall enough to require pretty minimal seatpost exposure. My comment wasn't that Coppi was on an ill-fitting bike but that the long seatposts often seen nowadays are not required to get a proper fit.

Whether or not the OPs frame fits is a question I cannot answer but I'm pretty sure that only having a few inches of seatpost exposed does not automatically mean that a frame doesn't fit.