The ink marked U-939d was producedin the years 1898-1899 and waslike the other 6-3 ink marked specimens amongst the very firstinsulators produced at the Victor plant . The unit on the right is an intresting newly reported variation on this design . It's crown has a difrent more fragile profile with a much smaller firing rest then all the prevously reported examples It came from Kansas City and was firstaquired in a box of random insulators by Jason Tounsend . Undboutedly this insulators origin is the same as the other U-939d specimens ... beingthat it was used to support DC trollie feeder cable lines for the KC trollie system . My suspicion is this piece was patternd after the experamental "Locke model l" and some of the pieces dug by Ken Willick in the attic dig They may have had problems with the very small firing rest being stable in the kiln and changed the design for one that would be more stable in the kiln . The U-939 has been reported in both brown and white and all variations could be considerd very scarce to rare with only a handful of surviving examples known. Both of these have marking 6-3 in black ink [id=408897708]