Modified Kennedy Half Dollar?

[DustDevilMarc]

I have now searched through four boxes of half dollars and found no silver. I did find this Kennedy half dollar.
It is plated in some metal (zink maybe?) and has two dates stamped on it.
On the left is 1960 and on the right 1985.
Any ideas why someone would electroplate and date stamp a Kennedy half dollar?

 

[50cent]

Ah yes, I've come across this rare half variety otherwise known as PMD, or in this specific case, "the knee slapper".