Installed the ICOM and lined it up with the GMA240. I taped the two trays together, then removed the ICOM radio from the tray. Marked the mounting angles using the holes in the tray. Removed the left & right angles, center punched and drilled four #28 holes. Assembled the angles, screwed the two lower trays in, then added the radios. Fit looks good, so I added the GTN650 tray followed by the radio. I lined up the radio, then taped the tray to the two lower trays. Removed the GTN and marked the holes on the mounting angles. Removed all trays, drilled the angles for the GTN tray, reinstalled everything. Fit looks good. Next up is to fab some kind of support near the aft end to tie the trays together.