1843 Liberty Seated dollar, a plain edge variety, altered, or fake?

I have a 1843 Liberty seated dollar that I bought at a coin auction over 30 years ago. It has a plain edge, not typical of the reeded edge for this coin. The edge itself is very slightly rounded with no signs of abrasion. A closeup of the rim resembles that of the Gobrecht plain edge pattern dollars of the 1830s. The fields of obverse and reverse are very clean.