Seems your frigidaire there is older than a 1933. Look at some clips from this story:
"Frigidaire, stung by the continuing loss of market share, struck back in 1933 with its Meter Miser refrigerator, which was advertised as consuming only as much energy as a light bulb, and costing less than $100. Frigidaire's engineers "one-upped GE by using different technology—a rotary sealed compressor in place of a piston type, coupled with a simple and inexpensive refrigerant control."
" Until 1930, engineers had only toxic or flammable refrigerants to choose from for their systems. Sulfur dioxide, methyl chloride, ethyl chloride, or isobutane were used in virtually all household systems until the General Motors Research Laboratory synthesized chlorofluorocarbon refrigerants at the request of Frigidaire in 1928.
You can probably date yours pretty close if it's using freon refrigerant
The discovery was announced in 1930, and Frigidaire magnanimously sold the new refrigerant, called Freon, to anyone who wanted to use it. Before long, the other refrigerants disappeared and the chlorofluorocarbons dominated nonindustrial refrigeration until recently, when scientists discovered that the CFCs damage high-altitude ozone. "