Sorry, trying to understand here. You decrypted the archive and then edited some data files inside the backup folder? And you moved the original encrypted archive there? Or am I misunderstanding something? I have a decrypter from uuksu's GitHub, and can extract the same data and graphics.
About keeping the translations... I'm assuming you're editing the rxdata files to translate? Maybe try instead of moving the original rgssad into the same folder, have the extracted data and graphic folders in with the game and temporarily move out the rgssad archive.
For decryptor i use from Falo ( i also have uksuu haven't tried it yet )
So for editing context :
1. I create new rpg maker xp project ( fresh clean ) lets call it gameProject.
2. I decrypt RGSSAD Encrypted Archive from FantasM Folder.
3. I got 2 folder from decrypting that ( Data and Graphics )
4. I copy this 2 folder into my gameProject.
5. I do some edit on databse such adding new item or skill then make event to give player item / skill that i just made ( gameProject ). [ More note at the end of the post ]
6. After i finished from point 5, i copy 2 folder ( Data and Graphic ) from gameProject to FantasM folder so inside FantasM folder now there's 3 folder :
1. Audio( from the beginning after extract FantasM.zip files )
2. Data ( from gameProject )
3. Graphics ( from gameProject )
7. When i play the game inside FantasM Folder with RGSSAD Encrypted Archive still on the FantasM folder the game will use data and graphics from this rgssad encrypted archieve file , so to make the game use the Data and Graphics folder i just moved from gameProject, i move this RGSSAD Encrypted Archive somewhere else ( lets assume on other disk with folder named "Backup" )
8. When i use point 7 the game inside FantasM Folder is able to use Data and Graphics folder that i just moved from gameProject but the Translation is gone its turn into Japanese. ( I can get my custom skills and items i just made on gameProject )
Note for point 5 :
My System Locale is Japan, i set it via control panel > region > locale. So when i open gameProject with RPG Maker XP Editor, Map and Database name is written in Japanese ( before i change the system locale it was "???" ).
Glad to explain with picture on next post if needed.
Thank you for responding to my question.