Everybody has heard of St. Louis Mallable Co,'s spools but nobody ever shows there wire holders. I have several porcelain spools with different markings of the No.30 type spool and one No.12 spool. Someday I hope to just get a clear glass example to add to my collection. I've been told there are still ones up in the air around St. louis. Wishes, wishes. Here is a photo of the St. Louis Mallable Casting Co. lag screw wire holders I have. From left to right: St. Louis on front 39 on back, Next St. Louis/ 37, next same different color, after that St. Louis embossed on front No.370 embossed on back. The last three are embossed St. Louis on front, No.370 /Pat No.1,709,477 which refers to Line Material Co.'s patent for a porcelain body with a lag screw etc in it. The two on the end must have been a improved or just a more beefier version of the 370 style. If you have any info pictures or catalogs showing the insulators avaliable from them I would love to see them. Their castings and insulators were always unique and stand out among others.