The one I'm looking for looks like this, but has an aluminum shaft. It's the one that came on my '74 PX10 when I bought it new. I replaced it with a Zeus right after I bought the bike because I thought the Simplex was ugly. I don't know what became of the Simplex, but it's been 30 odd years. Now I've come to appreciate oddball French components and I wish I still had it.
http://cgi.ebay.com/Vintage-Simplex-...QQcmdZViewItem