Certainly needs a good spec map, theres not much more you will need to do for the diffuse, but fix those scratches. IF you can pull a good specular off, it will come together a lot better, dont forget those subtle discolourations, finger marks, grease, stains etc.
just a couple tips for the knife: right now the metal looks very stony, probably due to all the noise you have on there, and the many normaled in bumps. metal is best defined as a smooth surface. weapons especially don't get dented and rough, as they are meant to be very strong and last a long time. instead, the coating…