Again, without having looked into the matter...
In the worst case, where the necessary gauge is not present, at minimum one would be required to:
- Obtain the texture(s) for gauge face and needles.
- Add to the panel mesh an entry for the gauge face, at the correct size and in the desired place.
- Make a mesh or meshes for the needle or needles.
- Place the needles via appropriate entry or entries in the cockpit folders hier.him.
- Add the Java code to drive the needle(s) in the cockpit's class (requiring a Java compiler.)
Outside a basic Java decompiler/compiler, the other stuff can be done with GIMP or Photoshop (there is a legal free version on offer, it being what I use), a spreadsheet and Notepad text editor. This is my tool set, the latter two of which comprise what I call the Poor Man's 3D Software Package. 😀
There's a member at another modding web site who calls himself Dr. Strangelove. He has put together a basic but functional Java decompiler/compiler toolkit based on JODE, and has made a little tutorial YouTube video on its use. A handy Java editor is Notepad++, also free, because it does context based color coding for much easier reading.
I'm no programmer, beyond having done some BASIC dabbling in the 80s and 90s. I managed to sorta kinda muddle my way around doing some Java, without having to drive others hereabouts to hair-pulling, I hope.
My point is that if one is motivated, at zero financial cost one can delve into most or all spheres of modding. It's eminently satisfying to enjoy the fruits of one's own creations!
Glenn