I started today by forming my seat pan a little further. I did not quite have the 86 degree bend and I wanted to have the bend correct so that I could correctly position the hinge. With the pan formed I located the hinge at each edge of the pan. I drilled the outer end holes and then used the other piece of hinge to ensure the hinge was correctly aligned while I drilled the remaining holes. I then up drilled, trimmed the hinge in the middle and removed the protective plastic from the seat pan in preparation for riveting. After riveting I moved on to make two more seat hinges. I used a sharpie to layout the holes and after drilling to #40 I cleaned up the hinge with acetone. It seems to be the only thing that removes sharpie marks on hinges. The hinges are anodized so they look terrible if you try to clean them up with Scotch-brite.