Back in the day it seems that either seatposts were very shy or riders all rode frames that were too large. I’ve never found a classic post that is long enough and when I built my Team Pro I resorted to using a Campagnolo Centaur (MTB) post for its length while not looking totally inappropriate.
Scroll forward a decade and riders showed a bit more seatpost but the ‘aero’ offerings from Campagnolo and Shimano are still on the short side. When I needed something suitable I found a Selcof alloy post that looked right and was just long enough. I may remember to find it next time I’m in the workshop and if so I’ll post its dimensions.