The Motobecane/Simplex derailer on the Team champion was a drop paralellogram Simplex Super LJ. I'm at work and pictures are blocked, so I can't verify if that's what you have. It will say "Prestige Super LJ" on the back. The pulley bolts will be aluminum. It's worth more than you paid for the bike. The front derailer was not a Super LJ because they needed one with a stop. It's a SJA102. I have the set on my Gitane, but I've re-rebadged them back to Simplex.