Hi Eric,
is that a regular M5 fine thread screw? I am also trying to find the correct screw for this location.
According to the parts list it should be a sheet metal screw (DIN 7983; 4.8 x 16 mm). However the hole in the plate of my 230SL has a thread that fits an M5 screw.
The corresponding M5 DIN screw would be a DIN 966.
I am hoping that the owners of 230SL or early 250SL cars could take a look and letting us know please what they have, sheet metal screw or normal thread, and possibly length and thickness.
Thanks!