Hallo Donald,
Dated with the copyright of 1984, the German M.H. Mueller has made a catalog of Mississippi Riverboats.
With a lot of information about the history of the Mississippi / the Lords /the Races.
And also some kits of the Valley Belle, Bryant's Showboat and the Idlewild.
And the plans for the Indiana, America, Cape Girardeau, Gorden C. Greene, Pacific, Sprague, Belle of Louisville, Omar, Natchez, Robert E. Lee, Buckeye State, Thomas A. Edison, Wild Goose, Far West, Vega, Chaperon and Louisiana.
In that period, he has public a lot under the name DER STEAMBOAT MUELLER.
From him I bought in 1985 the plans-set of the Robert E. Lee (from my build-log) and "The Western River STEAMBOAT CYCLOPEDEUM".
Recently I have searched on the internet, but could not find him anymore.
Here are some thumbnails of some pages out of his catalog.
So, there must be some kits of sternwheelers.
PS:
Some post above, from Uwe, I saw the info of the Robert E. Lee from Constructo. With the scale of 1:48.
I don't know how some (English) country's named the scale, but if it is compare to "original/model", than it is not correct.
The original was 285,5 ft = +/- 87 meter.
By 1:48 you get a model conform this size from John Fryant:
https://steamboats.com/museum/fryant.html
Impressive: 6,5 ft. long. Almost 2 meter!
The hull of my model is 1:1 to the 1:96 drawings of Alan Bates and is 93 cm. Just a little shorter than 1:96.
Measured to the 25.2 inch of the Constructo, it is 64 cm, and that is around 1:135.
Regards, Peter