Instead of crumbly gypsum "sheetrock" drywall, I chose masonite panels instead. Much easier to work with, and far less mess and poisonous dust. This is the right front, which has been a challenge from the time I put up insulation. I had to do it in three separate panels.
To put up the 4' x 8' ceiling panels, my uncle and I had to use the same ladder-and-bottle-jack idea that we used while putting up the water closet ceiling.
The part of the roof where it bends upward from the front alcove to the main body of the trailer was a challenge, and we had to use the same method. With drywall this would have required far more work and dust.
My uncle had wanted to bend the panel in the front to match the front roof curve, but I convinced him it would be a lot easier to simply put up the panels to make a 90 degree right angle instead.
The lower left front.
The upper left front. We had to use two panels for this oddly shaped section.