[CR]Mystery 50's Front Derailleur help needed

(Example: Events:Cirque du Cyclisme:2007)

Date: Sun, 20 Apr 2008 11:30:58 +0200
From: "Amir Avitzur" <avitzur@013.net>
To: Classicrendezvous <classicrendezvous@bikelist.org>
cc: Nick March <nicbordeaux@yahoo.fr>
Subject: [CR]Mystery 50's Front Derailleur help needed

One of my bikes has strange bosses for a cable operated front deraileur.

A shifter boss is on the seat tube below the saddle.

What looks like a chainstay mounted rear derailleur boss is on the seat tube near the chainrings.

Photo at http://www.flickr.com/photos/8210984@N06/2427637240/

These are on an early 50's French Randoneuring bike.

Can anyone identify the type of front derailluer that would have been attached to such a boss?

Amir Avitzur
Ramat-Gan, Israel