mystery piece large old solid copper pot w/ antique blue paint, vintage Nymph label

Early 20th century vintage solid copper kettle from some sort of washing or commercial kitchen apparatus (we think?). This has a center rod as shown, and measures about 11" in diameter x 11 1/2" deep.

We haven't been able to find out anything at all about 'The Nymph' as this is called on the red and aqua label. But we love old copper, and this is so pretty with the worn blue paint and green verdigris, showing just hints of the copper beneath. The interior is tinned, which is why we're guessing it was made for kitchen use - though it also might be for chemical processing or hospital use?

We found this in the huge collection of a farmer / collector / dealer, who had this in his barn for so long he couldn't remember where or when he found it. It's safe to say that it hadn't seen the light of day for about 50 years, and was an old piece at that time.

If you know anything at all about this piece, please email us, we'd love to hear from you. It's not all that often we find ourselves as completely stumped by a piece as this!