[CR]Pat 74 Campy RD question

Example: Events:Eroica
Date: Fri, 22 Jul 2005 08:37:15 -0400
From: <mmeison@aol.com>
To: classicrendezvous@bikelist.org
Subject: [CR]Pat 74 Campy RD question

On the RIH I recently acquired the rear derailleur has toothless jockey and tension wheels. I have always associated this with derailleurs older than 1974 (looks like the 1951 Gran sport on CR web site). Would this have been a mod by the previous owner or was this configuration available in 1974? If it was a mod by the owner what is the advantage to the toothless jockey and tension wheel?

Marty Eison
Dallas, Texas