These replicas are usually machine-struck (genuine cash coins were cast in sand, not machine-struck like modern coins), mass-produced for use in Feng Shui decorations. Apparently the evil spirits the charms are intended to repel either can't tell the difference between genuine coins and replicas, or they don't care.
The raised dots are supposed to be an attempt at reproducing the grainy appearance of a coin cast into a sand mould. A genuine cash coin of the Xian Feng emperor looks like
these.
Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis