As far as I know, but I can be wrong,
the boundig_box should be Type = bounding_box and serves only if you use the bones for animations.
The problem we have is above all in the damage model.
inside the "liveries" folder you find the "description.lua" file.
livery =
{
..........................................................
..........................................................
{"name of your plane", 0, "mirrors", true};
}