Guess great grandpa had saved them for decades then he kicked the bucket and great grandson needed more beer so he cashed in the stash for some spending money. Guess the liquor store would not take all the halves he had.
When I collected regularilly I always like to go to the Korean banks in my area. (There is a large Korean population in Orange county near los angeles.) I always did good with these banks. Lots of 90% & 40%. There was one spot that had four within a block. I asked a Korean buddy why I could always get a lot of halves from banks that had only Korean customers. They would tend to use even less than the average "white" bank customers. He said Koreans come over here and buy liquor stores in the ghettos then charge high prices. Most likely those halves were stolen and then spent on booze and cigs.