That's awesome! Once I saw a chain made out of stone in an ancient temple in Asia, people usually get confused about how someone could join stone rings without breaking them but archeologists know that they were sculpted from a single block like your chain
The Art of Whittling by Walter Faurot (1930) was in my high school library in the 80s. Learned the chain, ball in cage, and pliers. I was lucky enough to find a copy on ebay 35 years later!