Don't forget to rub your coins. Rub them often. Rub them everyday. Rub both sides. Rub a dub dub. YOU NEVER KNOW WHAT YOU MIGHT FIND! a LITTLE LUCK MIGHT RUB OFF YOU NEVER KNOW...
Perhaps they depict the two different designs proposed for the Gateway Arch Monument? Of course I'm kidding because the Gateway Arch was not designed & built untill 50 years later. I'd be interested to know the meaning of the two symbols.
The Japanese 5 Yen coin, pronounced "go en" in Japanese, is considered lucky because "go en" is homophonic for the word "lucky" in Japanese.