You could try Winnebagoparts.com. They are not related to Winnebago Industries but they are located about thirty miles from the Winnebago factory in Forest City, Iowa. Their actual name is Mobility R.V. They buy surplus Winnebago parts and then resell the parts.
If you contact them they will need your VIN number and serial number. They can then look up the exact part for your RV. They may, or may not have your part.
Safe travels. JD