I was able to get the kordyte tommy gun working with help from Cypress' tut (and TerminX's Cinema RASMaker'd) AND using MS3D 1.6.5 which I downloaded from FilePlanet (for some reason the latest Milkshape 1.7.4 won't import weapons for me though it does skin models fine?)
I use Photoshop Elements (and XnView) but the Nvidia .dds plugins can be used with Paint Shop Pro also.