A lot of progress this weekend. I installed the headliner/ceiling on Saturday. I was worried about bending the luaun but it went very smoothely. In fact, I did it entirely myself - I thought I would need some extra hands to help me make it come together.
One of the steps I took was to apply the polyurethane stain to the sheet while it was already slightly bent. Here is my high-tech jig that I used:
Another view:
If you look close, you can see how the stain ran and puddled into the middle of the sheet. Fortunately that part will be hidden by the shelves.