On the left is a White U-152 N-N (Pittsburg). Some soot stains show a small peck on the dome and a tiny split in the glaze at the wire groove. Kinda crude overall.

In the middle is a mottled Metallic Brown U-144 N-N (New Lexington; flat inner skirt). A pinky nail flake off the inner skirt is the only post-manufacturing damage. A small open bubble on the rear crown, and two small flaws in the glaze on the front crown are from day one. Awesome color.

On the right is what I believe to be a U-229 N-N as the 2-7/8" x 4" dimensions are the only exact match in Elton Gish's excellent unipart Porcelain Insulators guide. The color is very dark reddish Brown, and there is a tiny flake off the inside of the outer skirt as the only damage. The white area on the skirt is a raised spot of porcelain, not a flake. Not your usual beehive.

Inquiries welcome.