I have the "console" version of this radio, the one Alan describes.
This version has a wooden-horn Utah speaker inside, and space in the lower part of the cabinet for the batteries. As Alan says, the circuitry is pretty conventional. I traced it out and drew it up, and can send you a copy if you are interested. I can't advise as to value, because I have never seen another one. If the radio has value, it is in the case, I imagine, not the electronics.
The radio also came in a coffin-box version, which also has the birds of paradise on the front. Several years ago I ran across a fellow who owns this version of the radio, and I'll pass along his contact info if you would like.
There was an article about Royal Radio in the Providence Journal dated 4-26-99. It didn't really say much. I tried to contact the reporter, but he ignored me. Story done, next story! To my surprise, the link still works - see it at
http://www.projo.com/specials/century/m ... 6radio.htm
Don't expect a lot of good info from any of these - like you, I spent a long time trying to research the company and the radio, and came up dry except for the random contact with Martin.