I've reworked the rust this time. I ended up working from a black base with blueish highlights rather than green. The green patina I'm mostly familiar with is with copper, and I'm pushing more towards iron with this. I may have misunderstood your direction though. I've also pulled back on the rust stains on the wood, and added a light blue tinged wash to the wood in the shadow areas, to try and differentiate the wood parts.