I used various Dark golds and Bronzes on the model. Balthazar gold highlighted with Sycorax Bronze for the main ribs. Warplock for the side portals, drybrushed up with Runelord Brass in circular motions and brighter towards the top.
Leadbelcher with a Nuln oil wash highlighted with swirls and a mottled effect of Iron breaker and good old Mithril silver; for the steel parts of the shock prow.
Still need to weather the tracks to add a bit of mud.