Everyone I talked to recommended using 1/8" plywood for the interior ceiling due to the radius. Unfortunately 1/8" plywood is not readily available here so I purchased 1/4" 4x8 sheets. I literally came within an inch of success twice before snapping the sheets. I then decided to "engineer" my way out of my problem. I built this jig to press the plywood into place. It took a couple of interations to get it right but once completed it worked as designed. The next slide will show it in action.
Building a Jig to Install the Ceiling Skin