The next step i had to fill in the hole were the command tower was with green stuff. Next was the scratch building of the main missile turret. I played around with a number of ideas but after a good long look at missile turrets online i settled with a hinge and piston design.
The main front weapon ( Doomsday Cannon ) always looked too big to me, the shells would take up so much space. You couldn't fit anything else inside let alone a full Guard company. So i added a piece of plastic tubing and filled it with green stuff so i could drill out a smaller barrel.
So i toyed around with the idea of adding another option onto the Doomsday cannon, I Really like multi barrelled weapons, so i thought why not put one on the Leviathan. The function of the multi barrel cannon would be to take down the shields of an enemy war engine ready for the missile strike.