Over the years of searching for info on companies related to my lag screw wire holder collection, I've come across some interesting ads which lead me to more information leads. In this lot the first in the row is from National Metal Moulding Co showing a square type wire holder, Next is two made by Blackhawk Industries in the 50's. I always wondered who made the no.3626 and no 3627 marked wire holders. Later I found some with a marking on the back of B-I (Blackhawk Industries).,Next is Hubbard & Co. styles, One from Superior Porcelain Co., A neat Knox Porcelain Corp. one showing their line of electrical items, Last is an old Fred Locke ad showing I think a gutter top with glass base. At the bottom of the ad it states over 5 million Locke insulators in use. Where are they at! I'd love to find some.