I did not wish to make the ‘correct’ analogy, as I agree with your comment regarding silver as too valuable a comparison. In 1943, the US issued its most valueless penney, the ZINC penny, due to a copper shortage related to the war effort. Considering Nelsons’ service as less than valuable, I thought a zinc penny was appropriate.
steel, but coated in zinc. Now they make them out of zinc, and coat them in copper. Hm.