If you mean the rear changer with the red background,
Berto's Dancing Chain identifies it as a Simplex Tourist 303. I ride it daily to work on my Sun Manxman http://www.peterbrueggeman.com/cr/sun.html
It shifts very well. In my experience, you have to center it fully on each freewheel cog to ensure the chain doesn't ride on top of the cogs. I'm guessing that this is due to the forward positioning of the pulleys but I don't know. This is no big deal since you know where each cog is positioned on the shifter. It shifts onto the largest sized freewheel cog fairly quickly. ...................................... Peter Brueggeman San Diego California email@example.com
"...On the CR page, French components, a long cage Simplex is shown in the header but not discussed. Can anyone, please, explain the particulars of this long cage Simplex rear mech?... Richard Cielec Chicago, Illinois"