Why the designers chose poo brown for this pin is anyones guess, but i really do like the Maverick pinball. (maybe brown is supposed to give it a cowboy feel or something ?)
Like Marty said, tape up n give it a go. Get a sample of the brown first and test it somewhere. I think you will have to invest in a airbrush kit.
There have been a few different posts as to different types of airbrush set ups. Even the local TAFE runs courses on spraypainting etc. A good skill to learn to bring the best out on every pinball.
Photos of MAVERICK would be good.
Even before n after shots are always popular on here.