Diffusion on a flat surface

Hello,

First off - i want to recreate a surface i saw on a flash app.
It´s a virtual clone of a drum-machine.



I don´t really know how they did the surface.
I thought with a gradient mesh and very subtle changings - did not work out...

same goes to 3d diffusion since its flat

anyone got any clues leading me in some direction?

thanks in advance

Wow, just wow :)

Thank you very much for your fast reply, even more for the supplied file.

good karma

greetings, mike