In looking at it, I think it's a later edition made by the King Richards trailer service? Who knows but it's different from most of the Benroy's I've seen. Note, the square cornered windows and the ribbed siding.
http://siouxcity.craigslist.org/rvs/3032700279.html
Looks to be mostly there.
*edit*
Not sure why I typed "Fitzpatrick" earlier. Edited to remove that goof. Fitzpatrick was the name of the company that Bennet worked for when he made the first prototype in 53, as documented here:
http://outbackteardrop.com/benroy.html That's what happens when you get old and only retain 1 out of every 10 words you read.
