OK, Woody,
Sorry, I know what you are referring to. Last week I starting stripping the cab of my 54 3100 Hydra-Matic truck and that material chipped right off. I could not tell that it was the felt material - I though it was some sort of tar-based body-panel sealer. Sorry - I do not know what that material is nor where to obtain it (luckily my cab is rust free and I will not be taking those "ribs" off).
Tim
