Here are the latest monthly 2019 Kriegsmarine M3 NEPTUN keys and procedures made perpetual, revised to 20xx for usage until 2100. The contents of the tables have not been changed.
However, since the key tables are for M3, the Officer to Officer instructions which were originally included were written for M4, and have been excluded to avoid confusion. If these are still required they can be obtained from the 2019 procedures, www.enigmaworldcodegroup.com/m4-advanced-procedure
Barracuda (Neptun)
The cipher for fleet operations. Barracuda was used from May 1941. It was never broken.