I found a .56-50 Spencer rimfire cartridge (U headstamp) at the Canton TX "First Monday Tradedays" today. I wasn't expecting to find anything of interest and mostly went along so my wife could do her shopping. One vendor who had some guns directed me to another vendor who was selling ammunition. Sure enough, he had a few items of interest. I walked away with the Spencer cartridge, three .41 short rimfires in excellent condition, a .45-70 blank, and a handful of .32-40 Winchester cartridges. He had a couple of other things of interest, some different blank cartridges, but my pocket money gave out.Made for a great day as far as I am concerned.