It seems to me that I've read about some toxicity issues when cooking in untinned copper. Don't know if that would apply to a boiler since there's probably nothing for the copper to react with. OTOH if you're trying to purify water in the field that has a high mineral content then it might be a concern.

I did like the idea of those handles, though. You'd be a lot less likely to smoke your hand than with the bail over the chimney approach.

Ed