I picked up square shanked Stanley screwdriver bits  (and Yankee bits) in a
hardware store about five years ago.   In some of these old hardware stores,
you'd be amazed at what is hanging on the displays.   The worst thing that
ever happened to these stores was going to "sku" numbers for the computers.
Then it became "necessary" to get rid of all of the obsolete stock because it
didn't match the new system.   One old hardware store here in BR had
everything, a lot of it in drawers or bins of misc. plumbing or electrical
parts (most at the original ten cents each).   You could find anything to fix
your 60 year-old house.   Now it is sterile as a Home Depot or Lowes.   Oh
well, that's progress.