Hi, What I think you have to do is move some points in the UV map to fit the texture better (donīt know if this has a HEX editing effect...). In your base object use the "UV Unwrap" modifier, press the Edit buton and move the points you need, in the UV map window, to fit the texture. If you want I can make a more in deep explanation for you but itīs very intuitive
Again, this is the standard procedure form common objects, I donīt know if moving the points of the UV causes the need of tweaking the hex file or something like that...