1. I assume that you are trying to dave with D.X.T 5, but iirc, the carepackages have no alpha channel. Go save them with D.X.T.1.
2. D.X.T.1 Generate MIP Maps
3. Try downloading the attachment in my stick here:
It lists out the location of every weapon file in the game. Problem is I'm not getting a lot of feedback so I dunno if I'm going to be able to add in other stuff at this point. Attachments are in there though.