Here is somemore pics of a timing pin. This one is made by (spelling?) Assenmacher tools.
The text is from a Mercedes special tool site.
Engines 601, 602.91 /93 /94 /96, 603.91 /93 /96 /97, 605.91, 606.91 /96, 617.95, 602.981
pdf on how to use the timing Blocking/Locking pin
http://www.ps2cho.net/downloads/MB%20CD/W124/w124CD1/Program/Engine/602_603/07.1-8410.pdf
Timing infor might be found at this site:
http://www.ps2cho.net/downloads/MB%20CD/W124/Main.html