Jim, If your having to pull the quarter to the trunk extension then I would slice the quarter skin from the bottom and follow the wheel oepening up towards the top going just past where the quarter fits good. I would then either clamp it with some vise grips or cleco pin it or even tech screw it. The thickness of the blade of the cut off wheel will get you there. One thing to avoid when putting panels on a car is creating tension on a panel especially a large on like a quarter. You are very fortuante that those Sherman panels even come close to fitting. I had to totally reshape their parts to fit on my last Road Runner. I hope this helps.