Whilst we're on the subject of Chaos Dwarves, these are Magister Militum's FOG301 Goblin Bolt Throwers, more than usable for the Chaos Dwarves.
Note that MM's website says you get 3, but the pack I got had 6 in, each with 2 crew. Perhaps they intend you to put 2 on a base.
With just 2 crew on a 20x40 base, it looked a little empty, so I added some spare GW Goblins and figures from MM's Goblin command pack.