Since the Chaos Dwarves and Skaven have both provided their services to other Chaos Factions. Would it be possible for them to occasionally bargain with each other?
I can imagine they trade sometimes, I mean they worked together under Archaon, but before probably sometimes but nothing large scale I don't think. I imagine even after being corrupted by Chaos some tusked Dwarfs still don't like the Skaven cuz Grudges.
I don't know if Chaos Dwarf and Skaven tech would mix. The Chaos Dwarfs forge War Machines by infusing them with Daemons making them sentient Daemonic constructs. While Skaven build ramshackle Warpstone constructs. I don't know how well a Daemon would take being squeezed into a shitty Skaven War Machine. Although a War Machine with the destructive force of Skaven Warpstone and the durability and stability of a Chaos Dwarf Daemon engine would be an awesome sight.
I think Skaven would be the more enthusiastic party involved in that. The Chaos Dwarfs would if Archaon forced them but I can't see them wanting to Forge with Skaven. That's like asking a Dwarf Master Smith to work with a rural human blacksmith. Again though a combination of thier talents, I assume, would yield quite deadly weapons.