
I used the Tambor as the "template" for all the others, since the Tambor boat was the one that I ~always~ had function correctly after adding back in the fore and aft guns... I do know this though about the whole thing:
1. While in the Captain's Office, you can swap ends with your gun, ~BUT~, always go to the crewing screen to be certain crew positions followed. If they did not, then put the gun back the way it was. Make certain the original positions came back in. You can go on from there, or if you want to try again, exit the area, the Captain's Room, back to the Main Menu and try again with another new career, or exit the game and come back, lather rinse repeat...
2. If you get your gun where you want it, and you have crew positions, you can leave on Patrol. Once on patrol, beyond the home port area, crew up the guns. Then Save the game, exit and return with a reload. Your crew should now show at Battle Stations when called. If you do not Save, exit and Load, they usually do not show at the guns, though they are on the crew page. This only happens when you move the gun.
3. Once you move the gun, it will be weird whenever you dock (the Save data is different), and the "upgrade" to the next gun is a 50-50 crap shoot of retaining the gun positions. Most times when that happened in testing, it did at least put the crew back in the Damage Team, but not always - hence the reminder green circle when coming back in, for the player to Save and move their crew off the guns.
4. With the current set-up, I was able to use the wolfeinsamer method of removing the "AdditionalRepository" text from the crew positions. However, now the gun was ~really~ strange (in the Save data) if trying to move it again, and then the crew positions usually did NOT follow... Use of the Coletrains method, where you completely re-build the section might be better, though definitely more involved in FotRSU than Stock, due to the differences not only in crew size, but the crewing itself.
5. Silent Hunter 4 is one strange beast when it comes to modding... that actually goes without saying... but all of this is back to the way it happens in Stock now, and the Coletrains & Others method do work....