In 1993, when first met the owner of the 10,000 sq. ft. facility that I work out of, he inherited this 100+ inventory of solid Oak and Galvanized Steel "crates" that were at one time manufactured by this facility. These circa 1950 Material Handling Trays were manufactured for companies like Northop to use as storage containers for various manufactured airplane components.
The use of these crates ended in he 1950's.
Exploring different adaptive reuses, this utility cart was created. The unit shown uses three trays with a fabricated solid wood top and castered legs.