I recently got this beautiful M-3460 N-N Thomas with blue-jean seam (BJS) marking inside the bottom skirt. Thomas insulators with the BJS marking were made around 1905 to mid-1910's. Bob Stahr recently found the patent covering this unique Thomas feature. The insulator was obtained from an older lady in New Hampshire. She told me that her mother got the insulator in the early 1940's when she lived in Middlebury, VT and her mother gave it to her in the early 1960's. The insulator has seen long service in various flower beds, as a planter, and recently as a decoration on the fireplace hearth. She heard of a rare insulator selling last year for a large sum of money and asked her son to see what he could find out. He contacted me for an estimate of value and later the lady decided to sell it.