Good evening Adriano,
no, I believe that Engbrecht has 5, Gillanders 3, plus 1 shared with each others, which adds up to 9. The other crewmen of were Charles Gunn (radioman), Pat Peterson (bomb aimer), Charles MacDonald (mechanic) and William Riome (navigator). They flew 35 missions.
https://www.bombercommandmuseumarchi...illanders.html
I leave the matching of claims to those who are proficient and interested in it.
Also, I still keep at your namesake Wilhelm Baumgartner. As soon as I have a breakthrough, I'll report to you.
Cheers,
Michael