So the next day I took the paint remover to them. As soon as it bubbled I rubbed the paint off with a hand full of sawdust. I was surprised to discover a very perfect gray blue under-coat, and rust, pitting, and dents that speak of age.
I now believe that I have a pair of decommissioned helmets from the First World War. Someone, somewhere, has found these and is selling them repainted the bright horizon blue. What I now have looks a lot more like what one typically sees on websites. If I'm right then this is a delightful discovery, and at a price I could afford!
One of the things I most enjoy about my collecting is the slow discovery of the right item at a good price. If I were rich I would have bought way too much stuff by now. But being impecunious I have the pleasure of special purchases that fall into my lap in memorable circumstances.