There's a diagram of the original cushion layout on pages 56/57 of the
U-Haul Illustrated Parts Breakdown Manual which you can download from the Document Center (located under
Resources on the left of this website). It and the
U-Haul Repair Manual are incredible resources - thanks to Donna D. and the other
Fiberglass member that made it available to us!
Here's the link for it.
Jeanne