I used to be a CSR (teller) at a bank, and obviously handled lots of money. I looked for coins all the time. Usually just found wheaties--but I actually did run across silver Kennedy's from time to time. The '64s really aren't too uncommon. If you go to your bank and consistently ask for rolls of halves, you will run into some nice stuff. You have to keep on it, though, because most banks don't get a lot of rolls of halves in.
I think my best find as a teller at the bank, was an entire roll of wartime nickels. I got a roll of nickels out to dump in my drawer, and I started realizing that they were older than usual. Come to find out, I had an entire roll of nickels from the early forties. I was pretty excited. I quickly stuck two bucks in my drawer and rolled the nickels back up to take home.
Rolls of coins are always a good way to look for old coins. It takes patience, and a lot of searching--but it is possible to find old stuff in rolls. My usual finds are silver Rosie's in $5 dime rolls, and wheaties in penny rolls.