unlike other army books which had extracts in White Dwarf, the Chaos Dwarf one was pretty much just taken from White Dwarf (and clearly stated to be such). I would say rare miniatures because they didn't make them alot..
Storywise, the book says they were Dwarfs which made moved to the Worlds Edge Mountians and gotten lost underground, making a city there.. Then, being near Chaos, they started to Worship the Chaos God Hashut, Father of Darkness. They then took many Orc and Goblin slaves and tried to breed there own type of Orc. The first type were the stronger Black Orcs, which were more loyal and orderly then normal orcs, but felt they were too independent, so killed most of them, then Hobgoblins, who were larger then normal goblins but not as strong as Orcs, who had sided with the Black orcs then left them and went to the Chaos Dwarf side.
Normal army list includes Hobgoblins with Animosity towards Orcs and Goblins, with Black Orcs, as well as Slaves/recruited Orcs & Goblins, with Black Orcs being more the leaders. Can ally with Chaos, or Orcs & Goblins.