SDK's are not all that friendly to read and understand.
I'll keep it simple. Every texture for everything has to have a .json attached to it. It tells the game what kind of texture it is and how to display it. It has to be included with the texture. Now the flags are coding/instructions for the texture. For this it's simple texture. If you're just modifying the texture, you don't need to change the .json entries, just copy it.
Yeah. I'm not going to be doing anything to complicated. Mostly maybe modifying a landing light if no one else does, or tinting. I did the tinting, since no one else seemed to be getting around to it. My next is a remove tint for the longitude. Only one person did it as part of a clean glass package.