Check with Dave Boyd and he can replicate your tank in aluminum with a new sender..
He's a vendor on this board, based out of Florida.
http://67-72chevytrucks.com/vboard/member.php?u=67490
Dave Boyd / Owner
www.boydwelding.com
ph:352-447-2405
toll free : 877-270-3576
fax: 352-447-2403