Here's another neat example of a catalog page matching up with the insulators. These strains are all unmarked but you can see they were made by the Circle F company. I also have the standoffs pictured on the bottom plus their cylindrical lightning arrester. Many of the main companies like, Knox, P.P.Inc., Fleron, Birnbach etc. were easy to match up with catalog pages marked or unmarked. If you could just have all that knowledge at your fingertips would be awsome. Thank heavens there are some sites out there that preserve these things.