Thank you for all the compliments! Jason modeled this in Aspire and machined it out of HDU. I then painted by hand with regular waterbase paints that I had laying around.
For those asking about finishing details-
The first photo is just a couple coats of primer on the HDU.
The second one I painted over the primer with satin black acrylic paint. As soon as the paint dried to the touch I wiped the paint off the peeks with hand sanitizer on a rag. I used hand sanitizer because I have a lot of it for cleaning up epoxy and paint.
The third is satin black acrylic paint and to create the "rust" I used orange and burnt sienna acrylic paint that I thinned with water. I very lightly mixing the two so that they wouldn't combine into one color completely to create more depth. I brushed those paints over the whole piece, letting the paint pool up in the creases and wiped off the high points. Once that was dry I thinned out silver paint and lightly dry brushed that on the points and blended with a dry rag where it needed.
The forth I just went over the rust color paint with a thinned light blue and light aqua acrylic paints using the same process that I did with the orange and burnt sienna paints. I could still see some of the silver and I wanted a duller metal look so I didn't add more.
I know there are paint patinas that you can get from places like modern master, but I like to see what I can do with regular paints that I already have. Some were even cheap 99¢ acrylic paint from Walmart!