At the front of the '56 Imperial gas tank (bottom side) is what appears to be some sort of a plug or drain. My tank had a slight leak here, in addition to a dry rotted looking hose from the filler tube to the tank, so I've pulled the tank in order to do a full clean up/seal the tank/check & adjust sending unit job. Can anyone please tell me if this plug is threaded, and can be removed by using a 1/2" square drive to remove it? Or is it meant to be permament, and I should leave it alone and just clean around it and POR-15 it to fix the seepage problem? I have a picture of it here: http://www.imperialclub.com/Repair/Fuel/1956Tank/Plug.jpg Thanks! Mike Trettin 1956 Imperial Sedan, Turquoise