Hello Nokose
Many thanks for your comments. I looked through Aces of the Legion Condor by Forsyth and Laurier as well as Condor: The Luftwaffe in Spain 1936-1939 by Laureau but was unable to come up with any verification of his claims as regards Republican losses. I was able, though, to update the thumbnail biography with an incident that he was involved with in August 1937.
Seiler.zip
Horrido!
Leo