DD just told me that the city has put in a floor in the Eleanor Burns "livestock" area - where she has hundreds/thousands of bolts for sale. Before, they had a dirt/rock floor. She had tables available where you could set your bolts on while you were still looking or waiting in line - they had signs up that said to put a rock on top of your pile of bolts and that meant that nobody else could take your bolts away from you. Thought that was very unique. So, don't know what you will be able to use to "hold" your pile of bolts. I might try to remember to bring some post it notes that says "reserved" on them and stick them on the top of my piles.