Hold on, before you make one by hand. I think there is a guy in Bilereca Mass. that makes a kit for the tub. I can't think of his name right now. I will try to think of it and get back to you.
Here is the link:
http://precisioncoachworks.com/willys-pickups.html
It may not be exactly right, but its real close. If you still want to make your own you may be able to get some of the parts from him, stake pockets etc.