You might also drop Dave Severson a line or a PM.
He does this kind of stuff all the time.
On my 70 ford pick up we just cut about a inch on each side away from the gas tank door and pulled out the whole pocket and all, along with the filler tube.
The filler tube was just behind the drivers door and the gas tank was behind the seat. After we installed a fuel injected motor the pump in the tank made to much noise in the cab so it had to be moved out of the cab. It's just like Chopper did with the VW gas door. Kurt