Faded colors of age Shodoshima Island

Shodoshima Island has much character to be discovered.  Just walking about near the port of Kusakabehonmachi area one can see very old restaurants and structures such as this billboard that has been faded by time.  How long ago was this sign erected and do these plaques even have relevance today.  This is another area of Japan that seems to be stuck in time and it's wonderful.