There is a number set stamped on the aft end of the cam, use exact replacement or call Schneider Cams, they did a M130 engine cam which makes the motor a high revving 6cyl monster. Quite fun in third pulling onto the freeway, (jeeze, we are doing 90 now, should I shift to fourth?) (yeah take it on up to max, put it to the floor and hold it there)

Get a replacement, skip the weld-up because of cost and metal compatibility, Mercedes must make the cams from meteorites,
Your cam followers and ball adjusters may be toast.

Better yet pull the head off and do guides too. and clean the combustion chamber.