Fuel sending unit gasket

Do not know the origin of the steel tank that came with my '69. I got both stainless tanks from Van's in Wisconsin. At some point we just have to play the cards that we are dealt. I used the lock ring and gasket that came with the tanks.
I have a lock ring wrench. In the beginning, I tried different gaskets and thicker lock ring offered by Mega Parts. They didn't work. That's why I used the Pro Seal. We do what we gotta do to solve problems. I have 2 of the new junk senders in the attic too!