I made the third-generation Firefly-class transport, Serenity. I couldn't find any up-to-date mods that had any roof-mounted cannons that looked/functioned like the Flak 30/38 used in the 2005 film, so I substituted with a long-range medium-duty turbolaser from SWACD. I also had enormous trouble painting/decalling/shading the ship to look like her counterpart in the show/film, so I kinda cheated and made a to-scale decal. In total she's 82 meters long and 52 meters wide, thruster to thruster, just like the "real" ship.