Shifter Knob Restoration

Curious How did you "rough" it up? It looks like you rolled it on rough concrete.
Sorry, I ment to add that. I heated up a wire brush and tried to poke and slide it across the plastic. I did not practice on anything first which I should have.
Then I painted some dark brown Testors model paint in the deep areas last night, lightly sanded this morning and hit the surface with some thinned out lighter brown. Then sprayed 3 coats of clear.