Try fibreglassing a straight surface. If it's covering the outside skin it will be rough period, but if there is a moulded inner surface it will look good and smooth etc, but that's extra weight and complexity.
Looking closely it's a little rough around the edges and I couldn't vouch for the extension, but the price
certainly reflects that. They mostly come with Yanmars now but it has volvos - I wonder if they were added later.
DL - agreed on the layout but outing the forward heads behind the forward bunks is a bit of a no-no these days.