An Iron Warriors list with only one heavy support and one obliterator cult?! Am I seeing things? Good for you.
I agree with Archer, you have too many points in HQ for 1k. Drop either the prince or the lieutenant, but I'd prefer to see the prince go. Unless he's a crazy converted mecha-monster, I don't see the reason why an IW list would have one, fluff-wise.
With the points saved, I'd bulk up the CSM squads a little, or get another obliterator as well.
If you keep the lieutenant, drop the melta bombs as you already have the servo arm, and bionics rarely work, so drop them (I kow the model has bionics, oh well.)