Pepsi can with upside down label

[clueless]

My mother has a Pepsi Can from about 1977 where the label is upside down. It has been opened as she didn't notice it before seeking to quench her thirst. She's held onto it all this time and would like some idea of the value if any and how one goes about selling such an item._x000d_
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Thanks in advance for all your help []_x000d_
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Clueless