Brown CNR and CPR porcelain insulators. Both appear to be made by Pittsburg. The CNR is a rare find in the Northwest; all examples that I have seen were found on the Milwaukee Line from Washington into Montana. I suspect they were glazed brown and slipped into shipments of insulators to Milwaukee Railroad to supplement or replace shipments of the more common U-148 Pittsburgs that are found throughout the same area. Less than 6 known that I'm aware of. I got the CPR at the San Jose National Show. Its origins are unknown. Although it looks authentic, its source and authenticity are a mystery at the moment. It is the only one I've ever heard of.