[url=http://www.forgeworld.co.uk/en-GB/Leviathan-Pattern-Siege-Dreadnought-Body]The body - £46.00[/url]
[url=http://www.forgeworld.co.uk/en-GB/Leviathan-Dreadnought-with-Storm%20Cannon-and%20Grav-Flux-Bombard]The body, Storm Cannon and Grav-Flux - £72.00[/url]
[url=http://www.forgeworld.co.uk/en-GB/Leviathan-Dreadnought-with-Siege-Claw-and-Siege-Drill]The body, Siege Claw and Siege Drill £72.00[/url]
[url=http://www.forgeworld.co.uk/resources/PDF/Datasheets/LeviathanSiegeDreadnoughtRules.pdf]And the rules can be found here[/url]