David Hall: While the 1939 Oregons are the lowest mintage issues in the Oregon series, they were saved at the time of issue and are not that hard to find in Gemmy condition. That said, the 1939-S is the rarest of the 1939 Oregons in MS65 or better condition (by a small margin over the 1939).
The typical 1939-S Oregon is beautiful and mark-free. The luster is of the satiny variety. They come nice!