Could you remove the archs from the sides of the ship, replacing them with a texture/skin that look like archs?
Then use those polygons to make 4 towers on the church/cockpit bit at the back on the top. The coffin is obvous from its shape but the church is a bit bland.
You said about making it a generic religious ship but picking a house would give you more scope for design. Then you could pick between a shintoesque or chrisianesque style. Further to that, the churchs in America, Germany and England look different and could be an inspiration to refine the ship a bit more.
