Fatman Dollar. What Do You Think?

These are both common and commonly forged. Your example ostensibly dates from 1921, and there's nothing about it that I see that sets off any alarms (incidentally, you'd be better served inserting your photo inline than linking to an external website).

To find out if its genuine, first off, putting it to the magnet test will eliminare some doubt. Next, an accurate weight will advance the evaluation process. Finally, determining its specific gravity will definitively authenticate or expose it.