>>545087041
No it's not packed, there's no alpha in any of the textures.
They're not named the greatest. I'm assuming the black/white Body_Mr is the metallic and the lighter grey Body_Mg is the roughness. Also assuming the O is the ambient (O)cclusion
>>545087107
The roughness is plugged directly in. I think it's this shiny in-game, that's how it is I guess