On 1960s cars, you may run into to the issue of securing hoses with Beru "flip clamps." These use the same 5 and 9 mm strap as the cotter key clamps, and may be correct for the top radiator hose and the lower radiator hose connection at the radiator. Mercedes still supplies the strap, and you can get the clamps from the Classic Center. Apparently these clamps were used where a quick disconnect would be useful for servicing.
I installed them on my fintail this afternoon.
Attaching them is confusing if you have not done it before. It certainly confused me. I could not find a step-by-step, so here is my technique.
-Size the strap to be used by wrapping the strap twice around the hose and add about an inch.
-Fold about ½” of the strap over the bottom part of the clamp.
-Wrap the clamp around the hose CCW twice
-Position the clamp with the model number facing you, and the screw head to the left. The screw should be fully turned out and the jaws of the opening pointed down, rounded edge on top.-Make a ¼” tab by bending the strap and tuck it into the “jaws” of the clamp.
-Push the screw clockwise 180 degrees to tighten the strap
-Use the screw for final tightening. The screw extends and pulls the strap tight.
See pictures which hopefully will make this clear.