• Vallejo “Carbon Black” (73116) pigment was added to the end of the exhausts.
• The gun barrel end  and tools were lightly brushed with AK Interactive “Dark Steel” (AK086) pigment.
• Mixtures of Abteilung 502 “Engine Grease” (ABT160) or “Bitumen” (ABT004) oil paint in enamel thinners – in varying concentrations – were added to various parts of  the engine deck, transmission hatches, running gear and fuel drum and oil can to represent stains.

Looking at theses images now, it seems that some of the decals have slightly misbehaved and are not quite settled on the surface as I would like, despite applying on a gloss coat and using decal softener. Oh well!