I started but cutting off the threads on both ends of the coupled, and grinding off the chrome from the insides. I did this just so that they would be brass on the inside, unfortunately the outside rings were not brass and therefore would always be silver no matter how much I ground them. They could be painted I suppose, but I left them silver.
I cut two circles out of a clear plastic sheet the same diameter of the inside of the outer ring. I screwed the threads back in to hold the lenses in place.