That's a tough one. You might end up having to find someplace local who can use your existing frame to fab something up.
Finding a local dealer would be a good first step though.
I've obviously got a different brand than you, but I was able to get my manufacturer to point me to their parts supplier for some body damage. The parts were too expensive to ship, but it was worth it to swing by Elkheart, IN to have them do the work. Not only did they have the parts, but they had a service dept. who could do the job.