Should be this one:
https://www.winnebago.com/Files/File...r%20Switch.pdf Don't take this as the absolute part link it's just what I found - it is from the Winnebago Owners Club newsletter( WIT Club)
Usually there is a sticker on the front of the transfer switch and it contains the model number. It will not be a Winnebago part number. But made by TRC Southwire Surge Guard most likely. Mine is a model 40100. By the way they make many other models of this 50a Transfer Switch that have more features including full EMS functions.
Here's the one in my Adventurer:
https://www.amazon.com/Surge-Guard-4.../dp/B00F4620OO
Here's a different brand installed in some RVs:
https://www.amazon.com/Technology-Re...dp/B00PVG2I3A/
Here's a link to your electrical parts list:
https://catalog3d.winnebagoind.com/2013/182386.htm
You can find all of the parts in your RV at:
www.winnebago.com click on Owners, then Owners tools. Scroll down and click Research Parts List then select your year and model.
The Winnebago part number is 181917-01-000 but you don't have to get it from Winnebago as it will cost more from them.
Here's a screen shot of your electrical diagram with the part number: