I finally got around to repairing this rare Jewel today . It is the three piece mold version of the unipart non-glazeweld Locke #100 (U-964b) . Only three of this U-964a version have surfaced that I am awair of and all three came from the Victor dump . The #100 was first catalouged in 1901 and was produced as a non glazeweld till mid- late 1902 after which they began producing them as two part glazewelds ... Evidence in the Locke dump seems to show they had a lot of trouble producing and firing these without them cracking during firing. The very first ones were produced with applied crowns [id=318960804] ,but they soon switched to a two part mold version in early 1902 . The two part mold version mostly saw use on the Johnstown and Gloversville Interurban west of Schenectady, N.Y. that was built during the spring and summer of 1902 . All of these are no names or have marking 1-8 . All of the non-glazeweld versions of the Locke #100 (U-964a ) are rare with less then eight of the most common two part mold version known, . This specimen with marking 6-1 is intresting in that it was likely produced after they switched to making these as glazewelds and Locke stopped offering them as "made in one piece" ... The answer to these pieces late production was discoverd in the Ohio Brass cataloug of 1903 where these were offerd as ether glazewelds or non-glazewelds under difrent cataloug numbers. OB was a major seller of Locke insulators befor they started producing their own around 1905-06.