There is a "wanted" section in this forum. Scroll down and you'll see it. Post up what you want and people may respond. It's under the "For Sale" section, where you can look to see if anyone is selling parts you may want.
You can also try
www.ifsja.org for more "wanted" and "for sale" areas.
If you don't mind buying new replacement parts, you can try
www.bjsoffroad.com and
www.teamgrandwagoneer.com. Though Team Grand Wagoneer does tend to have slow shipping and less than stellar customer service. But if you're patient, the parts will eventually arrive.