Hey ! 3 years later I finally found the solution.
Like @Unnam8D, my mandalorian assault armor looked like in the screenshot from @darthbdaman's Mandalorian Armor Fixes mod. So I downloaded the mod to see the files and check if they were already in my override folder. And they were ! I think this mod was installed through the community patch or another mod. So first you will need to delete the files from this mod in the override folder. It will bring back the vanilla icons for the class 8 mandalorian armor and the class 9 mandalorian battle armor, along with bringing back the vanilla model for the mandalorian assault armor (the vanilla model being the classic mandalorian armor disguise).
Then you will need to delete the files from @JCarter426's mod. What I did was copy-pasting the option A files to the override folder and deleting them, then doing the same operation with the option B files. This way you can be sure that you've deleted all the files. Finally you can re-install the mod properly USING THE INSTALLER (this is very important, it didn't work properly for me when I simply copy-pasted the files into the override folder). Also if you want to change from option A to option B or vice-versa, keep in mind that you need to delete the files again in the override folder before running the installer again.