Old Bottle of John Dewar and Sons

Hello my fellow whiskey lovers.

I got my hands on an old bottle of John Dewar and sons.
I got this bottle from my mother. It has been in her late husbands possession. He in turn got it from his father who allegedly got it as a graduation gift. That would put it probably in the late 1920 if the information is correct.

Does anyone got any specific info on this one? The label is quite damaged so I can't make out a year so age would be interesting to know. Any clues to a possible monetary value.

Gratefull for answers.

/chefren