I appreciate all of the help here. Thanks! I have not found anyone to recycle the tanks, but have found many who will dispose of them. I will look into refilling them.
Back when Blue Rhino was expanding, they'd take the old-style tanks for free. Now they'll only accept them as an exchange.
I'm not sure about other places, but where my son works, the container HAS to have that over fill valve on them or he can't fill it .