What you have purchased is a pedal pad, meant to go over your worn pedal, I think you need to cut or trim the original rubber from the metal core in order to get it to fit properly (at least that is what I found I had to do). But if you want the real deal, you can still get a complete accel. pedal from SLS. They show the pedal for a manual as available, the one for automatic is probably back ordered.
Best,
g
'64 230sl, fully sorted out...ooops, spoke too soon