Ace,
I can't answer your question directly, but the pictures on Ro§bud's WWI photo site (
http://members.home.net/flyingaces/archive1.htm) Show the top insignia on a LE Niuport 17 and the bottom insignia on a US 103rd Spad 13.
Furthermore, the original insignia for the LE was taken from the logo for Savage Arms. Take a look at this web page to see what I mean: Quality reprint of the Savage Arms catalog #24, c. 1909 (Second edition) (
http://www.savage99.com/catalog24.htm).
So, the bottom line is that I think the top insignia is the first one used. By the time the LE was rolled into the US 103rd, they were using the second one.
-Drew