They were purchased by a company called Martin Industries, Inc. There isn't much about them. The latest information is from about 2005.
It is very difficult to certify a conversion from either gas to the other without the approved manufacture's kits. As far as finding one is concerned, I don't know.
Good luck.
http://www.martinindustriesinc.com/
http://wiki.answers.com/Q/Is_Martin_...ll_in_business