I want a procedural texture on a PNG "Decal". How do I set up the nodes? Modeling a Nintendo Controller.  The label is rough and reflective, here's an image of it...



Looks to me like if you ran your fingernails over the black part it would be bumpy so that's what I am trying to achieve.  I figured my NOISE texture node into a NORMAL MAP node would have given some results but nothing...  I'm not seeing what I'm NOT doing right...



The .Blend file is here...

.Blend file of Nintendo Controller

Is it legal to also ask how I could have made the mesh topology better in the same question?  How the heck did I get to over a million faces!?!

Answered by @Rich Sedman, draft result (needs some tweaking):
The Principled Shader is configured with 100% roughness for pure black diffuse with no specular. This will basically produce black regardless of the angle of the incoming light - the 100% roughness on the black surface will basically kill all bumps and textures and simply render as black.

To address this reduce the Roughness and add some Specular to provide some shine to the bumps. 

In addition, the Noise fed directly into the Normal Map will be producing incorrect normals (the output of the noise is not a proper basis for a normal map - it will be in a random direction (so may point ‘inwards’) and it’s length will not be 1). Better to feed the Fac of the Noise into a Bump node instead, to generate the surface normal.