I had started posting this topic on "another" board (one that let me have my avatar photo of choice). As I stated before, not only do the "view first unread thread" arrows not work, I didn't know what category this would fit in, so I chose this one.
Anyway, I had posted photos of my old inlet sock (which was lying at the bottom of my tank) which was too big to grab the inlet pipe and had a useless plastic hook (left), and the new one which grabbed the inlet tightly (right). No rust on the old one.
Anyway, here's two photos of the rust-free tank inide surface, thanks to the inspection camera my daughter bought for me at Costco. First looks like a drain plug on tank bottom.