I had the same problem as I started stripping the hull of my Guillemot-L last week and I wish I had seen the tip on using angle iron. I used the attachment of the shear strips to pull the warp out of the end forms. After attaching the shear strips on both sides to forms 3 through 16, I attached a string to the center of the strongback and pulled it straight over centerline of the boat. The line position showed where the tip of the bow (and stern) forms should be located. The attachment of the shear strips firmed up the end forms and straightened out the warp. It took a few tries to get it right though.