Thanks, Nick

From my 500E literature is states that SL500 brakes are used on the 500E which led to me believe that the 129.451.15.12 part numbers on my rotors suggests that the SL300 brakes are used on the (Might be a bad assumption)
And agreeing with MB Doc they are changed completely on the 93 and later models. Not quite sure of the later/replacement part #.

They are definetly different that STD 124 chassis 6 cyl. brakes.

I've think my plan is to buy the Gas Slotted Rotors (ATE) and Axix Pads.

Rotors will get rid of the heat better and pads will stop better than normal pads with less dust. Low noise also.