1840-O Half Dime-Grade, Die Crack, & Variety?

Hi,

Please address:

1. grade

2. authenticity

3. variety type(if applicable) with associated variety #

4. verification of existence of a rare die state & its effect on added value to this coin: associated reference number(if applicable).

5. verification of a die crack near lower left rock and to the right of date & their effect on additional value to this coin

The weight is 1.30 g with a diameter of 15.43 mm.

Thanks,

mdpmedia