Can you say "Delta Sierra"?
The FIRST switch I pulled turned out to be the CLUTCH pressure switch.
I learned that after looking up MB Part Number 006-545-10-14-64.
So I went back under the dash and found the REAL STOP SWITCH!
Yep Part Number 0015450109 was correct as RONMAN said
The only good news was that the CLUTCH pressure switch was faulty, so not a total loss of time and $.
Parts now on order.

Relearned Lesson: Take your time, work effectively, and if things don't seem right - CHECK AGAIN.
(BTW I'm working under the dash by feel - Damned cataracts)

DUH!