there is a guy on RCC that goes by the screen name MTHead, that can make the cummings logo you're after, and it'll be chrome. he's very reasonable as well. here's a pic of a custom grill emblem he made for me for my yota crawler.
it actually has sorta brushed aluminum look, and has a satin black outline, and they are self adhesive. he can make you anything you want, any size scale.