Looked at where the transponder mounting brackets were hitting the diagonal brace, and cut a slot into the right bracket to allow it to pass over the diagonal brace flange.
Re-tried the fit and realized that with the diagonal brace rivets the mounting bracket is limited in how far right it can move without resting on the rivet heads. This resulted in the need to trim about 1/2" from the bottom left hand bracket to fit but not interfer with the rear mounting bracket of the GTN650. Measured and trimmed the left bracket so that the GTX 45R mounting cage will now fit on the sub-panel.
Decided to use nut plates to mount the GTX 45R cage bracket for similar reasons as the GTN650. However this time use #6 screws and nut plates as there can be more screws used to mount the bracket to the sub-panel. Placed the cage with the mounting brackets attached into place and match drilled mounting holes in the sub-panel, clecoing the holes as they were drilled.
Since this cage and brackets extends too high above the bottom of the sub-panel to use a rivet squeezer to attach the nut plates to the sub-panel, decided to use CCR-264SS-3-2 pulled rivets to mount the nut plates. Clecoed the nut plates to the center holes with silver clecoes and then drilled the rivet mounting holes through the sub-panel from the front with a #40 6" long drill. Debured all of the holes. Dimpled the rivet holes using the tight quarters rivet tool (with rivet puller) and dimpled the nut plate rivet holes. Mounted the nut plates to the sub-panel using the pulled rivets. (In future, would probably use LP4 rivets instead, as these were so small they were hard to pull and didn't sit absolutely flush with the sub-panel)
Mounted the GTX 45R cage to the sub-panel using An 507 6-8 screws.
Sprayed another coat of clear enamel on the center console.
