Sunbeam or Excelsior?

This photo has been identified as Joseph Christiaens in an Excelsior during the 1912 French Grand Prix.  Other race reports indicate that Christiaens drove a Sunbeam. If anyone knows which marques he drove, please comment.
 
The race was held on the public roads in and around Dieppe, France. By the way, Christiaens competed in the 1914 and 1916 Indianapolis 500s, and did well, finishing sixth and fourth.