[CR]Dating Campy chainrings

Example: History
From: "Phil Grizic" <pgrizic@haggie.co.za>
To: Classic Rendezvous <classicrendezvous@bikelist.org>
Date: Wed, 19 Sep 2001 09:41:32 +0200
Subject: [CR]Dating Campy chainrings

Have just purchased an old 25? year old Bianchi - with Campy Gran Sport on it. I remember some time back someone mentioned that you can date the equipment by the stamp on the cranks. Can't remember what the circle and the triangle indicated. Mine has a circle with a 2 inside it. What is the year of manufacture. Thanks

Phil Grizic