I understand that in 1964 the Philadelphia and Denver mints produced a variety of quarter with the 1965 reverse die. How can you tell the difference between the 1964 & 1965 dies ?
I think you may be referring to the Type C variety. Here is a pic to help you. This is very tough to find though. TC
I'm not into quarters that much, but I did just learn something new. And it is true about dumb questions, the dumbest question in the world is the one that you don't ask...