Paint on bottom of exhaust system...what is it?

[1KULC7]

Can somebody please clear up what is used for the bottom of the Exhaust Systems on the mid-years, especially the 1963. I have seen originals and it looks like somebody used a swab of some type and applied (swabbed on) a black protective paint of some type. Can somebody please explain what this is, and how does one go about reproducing this>>>many thanks.

 

[Ol Blue]

EBvette
It's been a longggg long time, but it seems to me that there was some black paint on the bottom of the mufflers. I wonder if it was from doing some painting as it went down the line.
Ol Blue
http://www.knology.net/~corvettes/63vett.jpg

 

[JohnZ]

See my response to the same post in the Restoration forum.