Two ways are top of the head for me. One is call some of the really good parts places like Winnebago, or several aftermarket type places and tell them what you want and they are likely to know oir you can do more shopping and sometimes do an online search to save a fair amount.
To get the best price, I normally dig out the part number, then armed with the number do a search for the part to find who might have the best price/shipping combo.
Parts catalog here will often turn up the correct part number:
https://www.winnebago.com/Files/File...GO/3wf329b.pdf
Speaking of the outside door or part of it?
Possibly page 199?
But also be aware that some part go out dated and we need to swap in a new part number, so how much to spend versus how much time to find better? It's always the same.
Pay the price or pay in blood and sweat!
__________________
Richard
Why no RV year, make and floorplan on MY signature as we suggest for others?
I currently DO NOT have one!