Early Style Lid Design. The Set Shown Above (from my private collection)  is the Version Illustrated in the 1931 Erector Catalog. Advertised as the "Climax of Erector Glory" it is the Only Example of This  Rare Set Known To Exist.

Only a Handful of Sets With the Later, Hudson Locomotive Lid Design Have Surfaced. These Rare Treasures are Highly Sought After by Collectors and Connoisseurs.