U-1663: Vietnam
2 3/8" X 3 1/8" (60mm X 77mm)
No markings {Dry Process}
Picture courtesy Bob Berry |
2 3/8" X 3 1/4" (60mm X 80mm)
No markings
Picture courtesy Bob Berry |
U number assignment from Worldwide Porcelain Insulators by Marilyn Albers & Jack Tod.