Help w/ a strange 1750 mark

[jackk]

I need help with this hallmark. This is found on a silver box with a cast scenic lid. Item seems to be 150-200 years old. This is the best picture i have (taken with a mobile phone camera). The left mark reads GD on top and 1750 on the bottom (very simialr to Russian marks). Right mark is similar to mark for Augsburg, Germany.