[dsraven]

if thinking about hammering in some beads of your own, make sure to do the ends of the beads first and also the edges of the bead sides. this captures the bead stretch and helps with the sheet distortion. try it on some scrap first. i have done this method before and used a couple of pieces of metal welded to another piece of metal so i end up with something that looks like railroad tracks. it doesn't have to mimmick the rounded bottom of the contour, just the edges of the contour, the rounded hammer head or rounded tool is going to push that contour into the middle of the railroad tracks. the tracks need a hard edge, not a rounded edge, so it will capture and stop the stretch of the material right at the edge of the bead.