Originally made by Lennox Imperial and marked with "LIG". In 1983, Mary Walrath, commissioned "New Imperial", the last company to own the Imperial name, to make them. The owner used an entirely different mark, an "N" superimposed over an "I," which stands for "New Imperial" (shown above).
It has Santas around the skirt and pine trees above the cable. In addition to the amber/marigold shown, they were also made in limited editions in blue, green and red.
After Imperial closed in 1984, Boyd must have obtained the mold as they are also known with the B mark for Boyd.
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