Fast tracking in a 3 day auction.   

Old  PRR railroad dark green glass insulator.The PRR Pennsylvania Railroad Glass Insulator marked with a "B" is a highly sought-after collectible item for enthusiasts of vintage railroad memorabilia. This glass insulator was used on the Pennsylvania Railroad and is a rare find with its unique marking. It holds historical significance and is a valuable addition to any collection of vintage glass insulators or railroad artifacts.  This one is presented as found.   It's dirty with years of diesel soot and grease.   The cool feature is the threads that were protected by the wooden bolts that never got dirty from the diesel smoke. We are told the lines strung on poles next to the tracks were for communications.  After having several diesel trains passing daily, the insulators often became covered with grime.  

This one is not showing chips or other damage but under the grime will be several molding marks and perhaps other stuff.