Thanks for the photos, Bob. I appreciate the extra effort that it took. I can see clearly how to make the adjustment.
If the notch sits on the bolt, then the angle doesn't shift.
I see the upward tilt of your antennas, but it looks like the slot isn't long enough to have the boom horizontal with no tilt. Maybe a little tilt is a good idea. It helped with my 4-bay bowtie antenna tests, even when I had a clear LOS path over water from the transmitters.
