c'mon, folks-- Those of us old enough to remember (barely) a time when train stations, depots, and terminals were in heavy use remember that in most of the larger stations there was always a shoe-shine stand. In Chattanooga Choo-Choo, the speaker asks the shoe-shine boy for information and then says "you can give me a shine." I grant that the shoe-shine stands were usually manned by African-Americans, and I grant that, possibly, that may be where the epithet "shine" originated. But in that particular line of lyrics, the term is perfectly innocuous.