First, breathe in . . . out . . . in . . out . . .
Now.
Most of what you said in your post is a little hard for me to understand, so I'm just going to go through a small tutorial-type thing here.
First step: Gmax recognizes a texture titled $whatever.bmp as a ghost, so that the gauges can be placed there without the poly or texture actually showing up. The texture must EXIST in the actual Gmax scene, so there should be a texture that is 512x512 (or 256x512, or 1024x512, or any of those multiples). So we first create this texture, then apply it in Gmax. I usually make a black bmp that has something written in red on it, so I can easily identify it in Gmax.
Next step: compile this model, making sure the interior and exterior models are made correctly (hierarchy, links, etc).
Third step: in the panel.cfg, specify a {VCockpit01} that has a texture applied as so:
{VCockpit01}
Background_color=0,0,0
size_mm=1024,1024
visible=0
pixel_size=1024,1024
texture=$pan1
Everything here is important. The background color should ALWAYS be black (0,0,0). The size_mm can be whatever you want, really. This just makes the gauges show at different clarity levels. I always set mine to 1024x1024 to start with, and edit as necessary.
The visibility MUST be set to 0, so that it does not show in FS.
The pixel_size in FS can (again) be whatever you want, but (again) I always use the same size as what I just made the size_mm, so that I can be SURE it will show.
If all this is not met, sometimes the gauges will be there, but will not be within the defined area of the texture. They might be outside the bounds, making them invisible. Lastly, the texture should be EXACTLY the same as the name you gave the original texture in Gmax, minus the bmp.
Fourth step (almost there!): You can have the texture that you added in Gmax ($whatever.bmp) in the panel folder of the aircraft, to make this next bit easier.
If you have CfgEdit, now is the perfect time to open it. If you don't have it, go get it
HERE.
PAUSE
If this has been helpful so far, I can continue with it, but I will have to go relearn CfgEdit to do so. Many people think CfgEdit will not work for ACOF, but it will just not show the bitmaps for the gauges. It can work, but takes some patience and re-editing of the panel.cfg after the fact.
Would you like to know more?