When I removed my fuel tank, the leak was not from the sending unit gasket. It was from a mass of epoxy glop around the fuel line fitting. Someone had sealed the unit with silicon and lots of epoxy. My IA was pretty livid at when he saw. With a Dremel, work and patience i was able to remove the epoxy and sealant. Yep, it leaks where the fitting is riveted to the tank.
And suggestions on whom can fix / reseal the tank? I've found a couple of places, including Woodstock Aircraft in NY.
Thanks very much again.
Gary