If you want to change item.dat of uke do /dl Uke first. Than you will have item dat.
If you have problem with ingame command send it to me I'll fix it for you. And chare the information here.

For som,e reason the colours and textures that I've made in blender hasnt't shown up. Is this to do with UV unwrapping the object first. If so, how does one do this and can you explain how it would work.