Both have suggested the weathering could use a bit of splatter. The truth is I have not tried that technique and am reluctant to try it on a model that I have finished to this standard. I think I will rig up a piece of plasticard with the colour scheme I have used and try it first.
Thanks guys though. You have an excellent Facebook group going there. Check out https://www.facebook.com/groups/WGCconsortium/