[SS Tim]

Well yes... and it illustrates why it would not be hard or impossible to have a different color sheetmetal, just expensive. Plus it is far more likely on twenty trucks than just one.

But to answer your question.
67 trucks came with the interior metal painted fawn (tan/gold if you will) as a base color with black vinyl. In fact panel trucks only came that way through the end of production.

When you ordered a trim upgrade the metal was painted a color to complement the trim color instead of the fawn.

So for example a dark green base truck would have a fawn interior with black vinyl. But that same dark green paint with a Custom trim package now received a matching mint green interior paint and green vinyl trim.

A silver or white truck would have red metal to match a red Custom interior.

Even a blue truck would have a different shade but still blue metal with a Custom blue interior.