old 1 qt Kerr Self-Sealing Mason wide mouth canning jars, lot of 4

Lot of four old round Kerr Self-Sealing Mason wide mouth canning jars.

We've been told that these jars are pre-war (probably 1930s) as the round shape was discontinued during WWII when it was decided that a square shape with rounded corners was a more efficient shape.

These jars have a few chips to the rims and there are no lids included.