Always thought it would be fun to have a SW. Derek had a lot of sources posted on the 3B Page:
https://cj3b.info/JeepLinks.htmlRick Grover's website is one I've visited often to find other sources, i.e. the salvage yards that may have parts.
The Old Willys Forum has wagon and truck sections.
WillysTech (can be found from above links). LOTS of information.