Are you absolutely sure this is a quart? The depth of the lid looks proportionate to a midget pint. My inclination, without seeing the base & lip as mentioned above, is that it is a 1970s reproduction midget pint currently valued at $60-$80. These jars have 971 on the base and 3 side seams - one down the center of the back and one on each side of the embossing. I think I can see traces of those in your photo.