The location of the bolt heads/rivets was marked using dial calipers to transfer the measurements from one side to the other and from one car to the other. Once marked, each location had a dimpled drilled with a number 80 bit. The area was sanded down leaving bits of the primer deposited into the dimples. The bottom car has the dimples and the top car has yellow rivets harvested from the MEC boxcar glued to the side using MEK.