Had these pictures already taken so I thought I'd share them. G.P.Co. marked insulators are in that "Rodney Dangerfield" class of harder to find pieces that get no respect. Other than a few small cable styles and a couple of common signal styles, the G.P.Co. marking and the specimens that have it are not that common. Not sure what the parameters were or who made the decisions whether or not to mark a unit, but G.P. is another one of those companies whose markings were random. Here we have one of my favorites, an upside down marking on their signature mini-signal. The left and right show how the markings could be stamped at different levels too.