need some help from Luftwaffe Experten on operational losses

[Sternjaeger II]

guys, I'm trying to find some details about three Luftwaffe aircraft that were shot down in 1944:

1) 1 Bf109, shot down on 12 Sept 1944 near "Halbustalt" (couldn't find the place, my guess is that it is in fact Halberstadt, Germany).

2) 2 FW190s, shot down on 30 May 1944 S/E of Brunswick, Germany.

both happened around a similar time: 11.20am.

I know that Luftwaffe docs are incomplete, but I was hoping in some cross finding of aircraft loss records on the area, or maybe just knowing which JG served in the area at the time.

Any help is really appreciated, ta!