I'm doing a 1989 Winnebago Elandan. I find that many of the parts such as headlights, door handles, etc. come off of standard vehicles. The inside door handles are Jeep, the headlights are off of a Volvo truck, the side markers are off of a Chevy van, etc.
Winnebago is good about sending you their part numbers and construction drawings should you need them. Just contact them through customer service. Many of the parts manuals and wiring diagrams are available online at the Winnebago website.
Good luck with your restoration!