There isnt a good view of the rod or avail adjment.
That's a fabricated piece, so a mystery.
Gotta get in there and check it out, also make sure the pushrod can't fall out of the booster, - resulting in no brakes ! !
I often have to make a "guide" out of something to keep the pushrod where It's supposed to be, usually a washer welded to a rod, welded to pedal mounting bracket assembly.