I found a location on the right center of the F-7105A center sub-panel to mount the Garmin GTX 23 transponder tray. I cut a vertical rectangular hole in the sub-panel 1 3/4 x 7 1/2" so I could slide the tray through the cutout. I fabricated to aluminum angles from 0.063 stock. Driled 6 # 30 holes in each angle for AN4 rivets. I had to cut a notch in each angle so I could bend it slightly to accommodate the bend in the sub-panel. I match drilled to the sub-panel. I clecoed the angles to the sub-panel and slid the tray into place. I marked the angles for #8 screws to mount the tray. I removed the angles, drilled the holes and deburred. I rounded all the corners and primed the angles. I riveted the angles to the sub-panel with AN470AD4-5 rivets. I temporarily installed the tray to mark the location for a cross brace.
