I have almost a dozen old family beads. I think they were originally on a bracelet but the old thread has rotted. The beads are 20 x 14mm black rounded rectangles, the back is flat, and the front is faceted. They each have two holes running the short way across the bead. I would like to incorporate the beads into a necklace. One problem is how to go back and forth between beads with a single hole and beads with a double hole. Another problem is how to have the beads lay flat. When they are part of a bracelet they lay in a straight line, but of course a necklace curves when it's worn, so the beads tilt. Thank you.