You could also try Santa Ana Plating in California - they chrome plastic. I haven't tried them yet, but my dad and I are prepping a batch of small parts from a '62 Olds Starfire to be sent to them for chroming. They were highly recommended by a couple auto restorers in the Denver area who use them exclusively for plastic and small parts.
Santa Ana Plating
411 East Alton Avenue
Santa Ana, CA 92707 http://www.chroming.com/
714.549.3323