Hilldale, and others,
Eons ago in the mid-1950's, in Boy Scouts, we had a great craftsman scoutmaster. He had us making leather stamps out of large wood spikes and carriage bolts. We'd use his hoard of metal files and some punches and chisels to make a basic form, then refine it.
Stamping leather, the soft spikes were plenty hard and gave us a start on a fascinating hobby. On some of his tools, then some of ours, he'd use cyanide to harden them, then later Kasenit. He'd help touch up little features, was a wizard with a file. I still have some of those tools upstairs.... I believe there is an article on his work in an old issue of Boy's Life magazine.