Thanks for the replies, guys!
Yes, the Kracker archive is a great source. I have discovered many interesting things in it for my research.
If I understand correct: Egon Reichstein and Alois Job left 8./JG 1 in the spring to fly in JG 11. In this time, Heinz Overhagen already flew with 8./JG 1 and stayed there till his final crash on 12 March 1944. Is there anything known about the aircraft he flew in during the summer of 1943? This period is the main focus in my research, hence the earlier topic about Miksch.