This 49 year old cabletop was squirrelled away with some others I had forgotten I had, not sure what the U number is but it's a good looking choco brown saddletop that is stamp dated 19 W 58 on the skirt at the side. It is my good guess that this W in a circle is the Westinghouse symbol. Insulator is mint. $4 + $7.00 shipping.