450sl. Standing in front of the car, looking down in front, locate timing marks on balancer, locate timing pointer. Now if 0 is TDC and the pointer is right on the 0. The # of degrees on the left side are ATDC and the #s on the right are BTDC. This is what I assuming. I know I'am real stupid at this but maybe some day I will have something to offer back at ya.

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Stable:
1973 450sl
1978 red diamond ice vette
1975 steel blue convertable vette
2002 steel blue dakota quad.

And the question is ???.

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5280BENZ
'07 GL450,'03 CL500

I would agree with your assumption: the crankshaft rotates clockwise from the front-numbers "before" 0 = BTDC, "after" 0 = ATDC

What you said is correct. If you look at the DIY Wiki here on the site at my Timing Chain article, you can see pics of the indicator and markings.
http://www.peachparts.com/Wikka/M117TimingChain

With my little silver mark for setting timing on 5°ATDC

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Current:
2021 Charger Scat Pack Widebody "Sinabee"
2018 Durango R/T

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1972 280SE 4.5
2014 Jeep Grand Cherokee Limited "Hefe", 1992 Jeep Cherokee Laredo "Jeepy", 2006 Charger R/T "Hemi"
1999 Chrysler 300M - RIP @ 221k