Yeah to make something transparent you need to make the file a png since that's the only thing that works well with transparency.
Change the material code [wing code area] to
material preset_1_equipMatL
{
technique
{
pass
{
alpha_rejection greater_equal 128
texture_unit
{
texture preset_1equip
.png }
}
}
}
material preset_1_equipMatR
{
technique
{
pass
{
alpha_rejection greater_equal 128
texture_unit
{
texture preset_1equip
.png }
}
}
}