1. I think R-Vision is still in business so you could try contacting the factory.
2. Find a dealer for your brand of RV, see if they can set you up or point you in the right direction.
3. Many RV brands have an owners forum for that specific brand. If you can connect with people in that setting, you could be on to what you need, too.
4. Keep up hope on forums like this one, lots of helpful people here. :-)
5. Keep trying Google. You may need to reword what you type into the search bar to see if you get better results. As you do this, you may notice that there are companies that come up claiming to be able to get owners manuals and repair manuals for anything made. I don't know how reliable they are, though.
6. Forget about the owners manual for you specific RV and get the owners manuals for all of the components in you RV. Such as a manual for the stove and oven, one for the AC, one for the furnace, ect. All Rvs are built with a collection of all of the individual components so there is little or nothing unique about them. My owners manual is a good sized stack of reading material, very little of which was printed or produced by the RV manufacturer. It's all from the manufacturers of the components.
Good luck on your search.