The rudder skins come together to overlap and rivet together at the forward end. However, you want a nice round surface to tuck behind the vertical stabilizer. If you just fold the two skins toward each other, you get a pointy junction that won't clear the vert stab, so we used a broom handle to introduce a roll to the skin.
First we duct taped the broom handle to the entire leading edge, then force-rolled the handle with vice grips. Image 3 shows the result.