Red, that's all well and good, but at the end of the day you still have to find some place local or non local to deal with your "old tank" just like the people in your link.
reading all your links is all well and good, but you're not going to convince the guy at whatever dealer/filler you go to if they think otherwise just because you quote some regulation. Right or not, it doesn't matter.
The lady at Suburban Propane even quoted the regulation you're quoting and said there are some exclusions. Maybe she's mistaken, just doesn't know, or is trying to cover the company's Ass, but either way you have to give some credit to what the person who does this for a living says.
Later
C