Here's a rarely seen U-1808 snow white porcelain insulator. Maker is unknown. Looks like a cordeaux style insulator with a funky slot top. These slot top insulators were a transitional insulator- they replaced the very early no-tie insulators. There was about a 5 year overlap in their production (circa 1910-15) before they were replaced by the standard cable groove style, although a simpler version was utilized in Norway at least into the 1950s. Has unusual vertical ribs around the entire inner skirt [https://www.insulators.info/pictures/?id=570314070].
One tiny glaze ping and teeny slot rough spot from Mint condition! First email gets this rarely seen insulator for only $85 plus shipping. Thanks!