The Navy Type 26003* key was used with every type of navy transmitter and some signal lights that used a Morse key on ships and aircraft and on shore from the mid-1930s into the 1960s, unless the set (like the TBX and TBY) had its own specific key.  As such it was equivalent to the Signal Corps J-37 as THE most important general purpose Navy key for many decades.

It is an excellent key.  I have several removed from USN patrol aircraft before the aircraft were scrapped.   It is based on the 1930s Bendix MT-11B aircraft flameproof key.

Mike / KK5F