The hammerhead is looking very nice by now!! Excellent job... can't imaging the amount of time you spend on it so far.
It is looking like a real fireplatform. GW's hammerhead look like a fish... with a big gun. Yours look like a skimmer tank, armed and ready to destroy!
I'll have to agree with Mango about the painting though. Especially now that you have put this much will and work into converting the model.
Are you trying to make it apear as if theres an additional recess in the plating? If not, I wouldnt use black wash to make it appear darker (You might not be, but it looks like it). Use a darker grey instead (Not as dark as the one you have used, if that's what you have done). Also, do not apply highlights over it. I think the highlights make it appear as if theres a gab in the plating (which I know there isn't), even more than the dark shading. Just thinking it looks a little off.
The above is just what I would do, if you wont... then don't!! I have no doubt this will look very good once finished.
What do you have to say in your defence!?!