According to my 230SL parts book, here's what is supposed to be there from top to bottom:
127 060 00 46 - Connector for tachometer drive
120 261 00 80 - Seal ring
126 990 01 40 - Cover plate
621 997 00 40 - Rubber ring (replaced by 621 050 05 06)
126 180 00 44 - Thrust piece
000561 008107 - Hex head screw for thrust piece
I hope this helps.
Rodd
Powell, Ohio, USA
1966 230SL, Euro, Auto, Leather, both tops
1994 E420