A) Grayson's destination in "Train 45" is LAUREL BLOOMERY, Tennessee. It sounds almost as silly a name as "Larrawhoomper," but it actually is on the map, and this was G B's place of residence at the time he and Henry worked together.
B) See Henry's c1931 self-published song pamphlet, Familiar Folk Songs As Sung by Henry Whitter for the correct spelling of his name. Dave Freeman, at County, sold me one of these for $2 or $3, out of a newly-discovered stash of the pamphlets, back about 1970.