I just read a wiki presented by pelican parts. It recommends using a line wrench. So....I just happen to have a flex head 10 mm line wrench. I managed to get it on the fan bolt so all is well. Thank you to everyone for weighing in, your advice is appreciated.

Now both cars are down, the 560 is awaiting some brake work while I am trying to figure out how to deal with the 1984 300DT. Big fun in the ole town tonight!!!

https://www.pelicanparts.com/techarticles/Mercedes-W123/14-ENGINE-Fan_and_Shroud_Removal/14-ENGINE-Fan_and_Shroud_Removal.htm