In short, I stumbled upon a mystery without really trying. It revolves around this postcard. It's a picture of the Old Courthouse in downtown St. Louis. The mystery part is that statue. I have a bunch of postcards featuring the Old Courthouse and an assortment of other photos, all capturing different moments in time. I've never seen this before and it really piqued my curiosity.
So, I went to the Courthouse today and spoke with a historian and an archivist. I thought for sure that the folks at the Courthouse would look, nod and say, "Oh, yes, this is ..." and instantly solve the mystery. Except they didn't. They had never seen it either!
The best they could do was confirm my theories about this card.
1) While it is postmarked January 1913, I think the photo was taken in 1907-1910 range. (Courthouse folks say may be a little earlier - 1905).
2) Statue is likely something from the World's Fair/1904 Olympics.
3) Likely was part of a very temporary display (year or less).
I've looked through a bunch of photos and some of my postcards from the era roughly but no dice. We'll have to see how this shakes out.