I worked for an aircraft interior shop for a while many years ago and helped one of their master carpenters make up a curved door for a bar in a very nice custom Gulfstream. He used about three thin layers of plywood (maybe 1/4"?), cross cut them, clamped the first one to a plywood form with the correct radius. Then he glued the second to the first, then the third. Then he covered everything with a cherry veneer and trimmed out all of the trim. Took him about two days to finish everything.
1986 Airstream 345 Classic Motorhome