FYI:
The backshell to that DB-9 is special because of the screws - the "Backshell 2" as listed by Vans. Remember, the backshell is not the plug! The backshell 2 has shorter screws that require a screwdriver (shorter than all of those thumbscrew-type backshells behind the panel) that do not interfere with the magnetometer that is part of the ADAHRS unit. (But they are NOT "non-magnetic" screws.)