Cheers for the responses guys, sorry for the lack of reply on my part, been busy with interviews for a new job (start in January!) and not done much painting recently. So I'm cracking on with my diorama, just need to pick up some plasticard on Monday. In the meantime I'm intensifying the weathering like you both suggested, I'm happy with the brown rust and just cracking on with the verdigris see if I can tidy it up a little.