well ill try another dime i ran across yesterday i think the d is for sure doubled at least i hope it is tks
In 1964 Mint Marks were hand punched into the Die. They cannot be Doubled as in Doubled Die. So you can't say doubled as in Doubled Die. It can only be RPM which is Repunched Mint Mark. Looks like a deterioration issue to me. IMHO.
RPM's do look like doubling sometimes. Here is a useful site for identification. http://varietyvista.com/07 Roosevelt Dimes/RPMs 1964D.htm