Linking this badge to Brehmer
The badges shown above provide clear links to Brehmer. Thanks must go out to Philippe DeBock whose analysis on the German Combat Awards forum made the link possible. As he stated:
I think these badges can only have been manufactured by Gustav Brehmer.
The grip mark I posted (see below - GB 50 PAB) as far as I'm aware of is unique to GB and can also be found on zinc GB luft flak badges.
The pebbling on the talons as mentioned by Tom Durante also is a typical GB higher grade PAB design characteristic.
We already knew that GB made high quality BM Luft flaks that design wise come very close to Juncker made luft flaks.
So the fact that this heer flak shares design features with Junckers doesn't come as a surprise. There for sure was a very close collaboration between Juncker and GB. If you look at the grade II & III PAB's GB also used the Juncker design for both wreath and Panzer. Further evidence of this collaboration can also be found when comparing Juncker's and GB's GAB designs.
Other links to Brehmer can be seen by this numbered Panzer Assault Badge by the Brehmer firm. The legs are very similar in design to the Flak badge, and more concretely the same “V” shaped notch exists on the retaining pin. While there is no single “silver bullet” such as a maker mark, taken holistically, the vast amount of evidence clearly links this badge to Gustav Brehmer.