wt1, I think you were almost right, it may be a name, but the second letter looks more like U, so Muller instead of Miller. I just found this about a Muller: •Jacques Muller (*1881 †1956) Aircraft constructor and pioneering pilot between 1910 and 1920. Living in Salinas, Kansas, Jacques Muller built one of the first airplanes in the US in 1910. The plane was named "Prairie Eagle". On 18 July 1910 he patented a propellor, on display nowadays in the Smithonian Institute in Washington. He founded his own company called "Jack Muller Aeronautical Enterprises". World War I started whilst he visited Luxembourg in 1914. He decided to stay in Luxembourg and became a pioneer of the paint industry, registering several patents for anti rust paint.
Now I will try to find some pictures to see if it matches.