I am working on attaching new 7 wingtips to my RV-4 and I was really not looking forward to creating fuel access doors for my extended range tanks
Low and behold, Jegs has the answer:
http://www.jegs.com/i/Jegster/550/40460/10002/-1
lots of uses on a RV for this, and it's a fair price considering the labor it avoids