I tried simmering about an inch of straight vinegar in the bottom to see if it would touch the minerals, it may have softened them a bit... but I believe it pretty quickly neutralized the vinegar as the CO2 bubbles that were audibly apparent at first stopped. I have a feeling it would take a gallon or more of vinegar to react with all the hardness in this kettle.
I did some more research and found a picture on the Alcoa website (
http://www.alcoa.com/global/en/about...story/home.asp) Click on the timeline entry for 1889 to see a very similar kettle, possibly a different size.
"Lightweight with a bright surface, excellent at conducting heat and easy to clean, aluminum seemed to be the perfect material for cookware and utensils. To interest cookware manufacturers, Alcoa developed the first prototype aluminum tea kettle. The tea kettle helped them get their first aluminum order for utensil production."
My kettle may have been part of that first aluminum utensil order in manufacturing history.