After much head scratching, I decided to go with a single tray from the Truss to the Firewall. I had several iterations of trays, different sizes and shapes before deciding on this one. I worked on laying out the components that need to be installed behind the panel. After discussing it with Chris (Wiring Guy), we both thought this arrangement was the most effective. It calls for the IBBS Backup Battery, VPX Pro, GAD-29, and the GDL-51R on the top with the GEA-24 on the bottom.
Once I finalized the order I set about to drilling the tray for the hardware.
Then mounted all the components.
It all mounted with temp hardware, I'll powder coat the tray before final installation.
I did goof up and switch the GLD-51R and GAD-29 when I drilled the holes. I will switch them before finishing. The GAD-29 allows more access to the D-Sub connector on the back of the GMC-507 Auto pilot controller.
I had the GO-40 CO detector left to find a place for. I ended up using the tabs that were already welded on the cross bracing. I cut out a plate and fitted it to the tabs. Since I wanted to use lock plates I had to install them on the plate, the tabs were too small to install the lock plates in them. Then mounted the CO detector on the bottom facing downward. I could have mounted it on the top side but the clearance to the glare shield (still to be fabricated) would be too tight. No harm in having it facing downward.