They are pretty rare. I looked for over 25 years before I found one. I've seen several sold on eBay and I was lucky to get one of them.
The early Simplex SLJ front derailleurs had a flimsy clamp that frequently cracked at the hinge. Here's a link to one that recently sold on eBay showing the defective clamp.
That design flaw makes these even harder to locate because so many have broken. I have 2 or 3 silver ones with broken clamps.
One other thing, the welds on the cage are very brittle. Any attempt to adjust the cage by bending it can cause the weld to break. I have several of these too. ;-(
Chas. Colerich Oakland, CA USA
-----Original Message----- From: Kurt Sperry <email@example.com> Cc: Classicrendezvous@bikelist.org Sent: Wed, Jul 8, 2009 1:32 pm Subject: Re: [CR] Gold Simplex Super LJ Front Derailleur
> Simplex made Super LJ front derailleurs with 2 different cable attachment
> points - behind the seat tube and in front of the seat tube. The front
> connections derailleurs used a short piece of cable housing between the
> Simplex down tube cable guide and the derailleur.
> The front connection models are far more common that the rear cable
> connection derailleurs.
I have always thought that the cable run through the clamp pivot in the front pull SLJ fronts was a neat design. I've never seen a gold anodized SLJ front derailleur with rear cable routing. If they exist, they are rare.