Hi
I can not with certainty identify the pilots Boelcke had with him from the start (11 Mar 16) of the temporary unit KEK Sivry...
However, as I interpret the German text is that Boelcke said it was three pilots, him one Lt and one non-officer. Further it was 15 ground crew etc..
I have
von Althaus as serving with
another nearby
KEK (Jametz), but both he and Boelcke were members of
FAA 203 at this period...
KEK Sivry still probably had only three pilots in early of Jun 1916, it is at least
certain that they only had three a/c...
The KEK at Chassogne Ferme (called Fokkerstaffel) who had 5 fighter a/c was later in Jun 16 amalgamated into KEK Sivry. Most sources also indicates that KEK Jametz was amalgamated into KEK Sivry shortly thereafter (dates differs a little)....so in early Jul 1916 KEK Sivry was rather big "unit" (nearly like some Jastas in 1918)...
Gunnar