We had an interesting thread going a few years ago. I came across the paper copy of the article recently and so it came to mind.
There were some concerns that the item in the picture might have been something other than a K-Horn; 1943 is pretty early.
But I see the K-Horn patent (2373692) has a application date of October 3, 1942. Therefore the design had been completed the year before the article. There is no reason to think the item can't be a K-Horn with Paul having given plans to Fairchild.
Perhaps our historian can enlighten us on the situation. At his convenience.
WMcD