If you look in the diagram, you'll see that each clutch pack contains a stack of friction plates and steel discs. I assume they are referring to the discs.

If it helps, I had my transmission rebuilt at a shop in NJ that does a lot of Mercedes automatics. They also manufacture and sell DIY kits. It may not be a bad idea to call them and have them assemble the correct kit for you:

TRANS SPECIALTIES | Remanufactured transmissions | rebuilt transmissions | transmission parts | torque converters

I didn't think they used lock-up converters until much later.