Flat Black over Gunmetal

I have no idea what Monogram is saying, unless they mean to paint the exhaust ends of the stubs black to simulate a hollow pipe. Normally, I paint exhaust stubs a dark steel or reddish burnt iron, depending on the era. Ends of the exhausts I drill out if pracical and then paint the drilled out area black to increase the illusion of an actual pipe. Super-detailers would likely replace the stubs with steel or brass tubing.

Rick

I think what they are aiming at is creating that muck over metal look that characterises most engines after a fairly short period of time.

Best bet take a look at some pictures of the real thing and see how they look. Most air cooled engines start out metal coloured, and then accumulate dirt in the nooks, crannies and cooling vanes, so perhaps a base coat of black, followed up by dry brush of aluminium or steel might give the right effect.

Karl