3 Vintage Clear Glass Corn on the Cob Salt & butter Holders

This is a lot of 3 vintage corn on the cob holders.   They are all in good condition.  I do not see any cracks or chips in them   These belonged to my parents who were married in 1940.  Not sure exactly when they are from.  Each holder has a compartment for salt, butter and the corn.   Each one is 10 1/2" long.  They are a heavy clear glass.