there is a reason it is not in the game. and there is a reason the opening post sais this is only the model.
The model isn't OB compatiable. If you were to use the one that was linked before, you would not see SMG3, but an error sign ingame where the model should be.
Can someone fix it please? http://www.darkterror.dyndns.org/smg3.7z I hope everything is in there. I would like to use the SMG3 in 2.21 too.