clad half error?

[port ewen ace]

1st guess is arc welder, but note the "a" and ghosting of letters. not solder, very hard metal, not magnetic

 

[cudamark]

Looks like it was drilled and then filled. Some solder, such as silver solder used in jewelry, is almost as hard as the coin. What year is this half?

 

[l.cutler]

I agree, might even be something like JB weld.