So, if I understand correctly, you made two image files, one for the right side of the body, and one for the left.
Make sure they are indeed saved as .jpg files, and not somehow .png files?
If that's not the issue, try replacing the body section of your code with this one:
material preset_5_bodyMatL
{
technique
{
pass
{
texture_unit
{
texture preset_5bodyl.jpg
}
}
}
}
material preset_5_bodyMatR
{
technique
{
pass
{
texture_unit
{
texture preset_5bodyr.jpg
}
}
}
}