Dear Nick,
Thank you very much for your advice. Sigurd Haala was an Oberleutnant in JG 54, for example, he signed two entries in Alfred Budde's Soldbuch:
http://www.jg54greenheart.com/BuddeSb.html
Here is what De Zeng and Stankey say about him: HAALA
, Sigurd. (DOB: 28.10.19 in Austria). (DKG). 28.06.41 Lt., 4./JG 54. 01.03.43 promo to Oblt./A1. 21.06.43 Oblt., in 1./JG 54. (n.d.) Oblt. in JG 54. (n.d.) awarded the Ehrenpokal.
03.09.43 Oblt., 4.(Jabo)/JG 54 appt acting Kdr. IV./JG 54 (to 14.09.43). 17.10.43 Oblt., 10./JG 54. 12.01.44 Oblt., with 10./JG 54. 18.03.44 Oblt., 10./JG 54. 01.04.44 Oblt., 10./JG 54. 27.07.44 Oblt., 11./JG 54. 05.08.44 Oblt., 11./JG 54. 08.44 Staka 12./JG 54. 21.08.44 WIA - Fw 190 A-8 shot down in Pl.Qu. 25299 and became POW. 01.01.45 Oblt., awarded the DKG. Credited with 42
victories. †16.06.97.
So, maybe there is a photo of him in a book about JG 54...?