1985 JAGUAR XJ6

THIS 85 XJ6 JAGUAR WAS BROUGHT TO MY SHOP FOR REPAIR.THE LEFT REAR GAS TANK STARTED TO LEAK AFTER I PUT 2.00 IN GAS IN THE TANK. MY SHOP WAS HIRERD TO REPAIR THE TANK. THE LEAK WAS IN THE (SEAM) OF THE TANK. I NOTICED THIS CAR HAD VERY BIG GAS DRAIN PLUGS IN THERE TANKS,ABOUT 2.5 INCH ACROSS WITH A ENTER PLUG 1.5 INCHES,A DOUBLE PLUG SYSTEM.EVERY CAR I HAVE EVER WORKED ON , HAS NEVER HAD A GAS DRAIN PLUG IN THERE TANK BIGGER THEN A 1/2 INCH. ON 5/6/98 I STARTED TO DRAIN THIS TANK ,THE GAS CAME