One like this
Campagnolo Super Record Seatpost 27 2 Fluted with Box Road or Track Classic | eBay
25mm.
I raced back then, so all we bought was Super Record when my pocket book allowed. If not, then it was NR. When the new index stuff come our from Campy, I had to have it but, they didn't work and had issues with it, so switch to DuraAce and never looked back.