This is the fourth style of CD 131 which was used on the Central of Georgia Railway telegraph line. It has no embossing with a {MLOD} and no mould mark. The color is rich blue aqua and when you view this insulator side by side with the W. Brookfield / 55 Fulton St. They look like two peas in a pod. Most of the no embossing CD 131's had some amber swirls as do the W. Brookfield / 55 Fulton st. I love this insulator as it has so much character. The no embossing style was about as rare at the Tillotson. I put around three of these into the hobby via trades.