Hi Buzpilot are you aware that there are several layers to Cod skins?.
I can only assume that the Nacelles live on another layer other than the one you have painted, i havent looked at the Blenheim yet.
You might want to do a flood filled test skin if you havent already to see if the nacelles change colour at least that way you will know they dont live on that layer.
Theyre like onions mate
Does that make sense? a lot of the time I dont, so the missus says