We just purchased a 2017 Georgetown 351. So far so good. The camera was reversed left to right as well. After some research on the internet and downloading the camera manual from the Forest River sight I changed it.
You pull the panel that holds the heater control, radio and camera monitor out of the dash. It's about six screws and then it comes right out. After you get it out there is an interface box, silver in color with wires and plugs coming out of it forward on the firewall. there is a small switch on top of the box marked normal/mirror. It will be on normal. switch it to mirror and reinstall the panel.
The camera manual is a little hard to find. Here is the link.
http://idn.tweddle.com/media/bundle-assets/RVS-3CAM5077_MANUAL_V3.pdf