Here's more info on "MAMA LET ME LAY IT ON YOU."

"Baby, Let Me Follow You Down" (learned from Eric Von Schmidt) is in fact a rewrite of "Mama Let Me Lay It On You" (recorded by Blind Boy Fuller, New York, NY, Apr 29, 1936), which Reverend Gary Davis claimed to have written.

There are, however, several recordings that predate Blind Boy Fuller's version:
Walter Coleman's Feb 8, 1936 recording (Chicago, IL; 90611-A-test), which remained unissued at the time (released version recorded Chicago, IL, 3 Jun 1936; 90611-C, both available on "Cincinnati Blues 1928-1936," Document CD 3519-2).

TONY RUSSELL, in "The Blues Collection, No. 52: Blind Boy Fuller," (p. 624) claims that Memphis Minnie recorded and released a duet version (with her husband Joe McCoy) as early as 1930.
Thus, Reverend Gary Davis' claim of authorship and his subsequent listing as the author of "Baby, Let Me Follow You Down" on "The Last Waltz" is IMO unfounded and the song is most likely traditional.

As ERIC VON SCHMIDT points out (in his 1993 SongTalk interview):

What finally happened was that Manny Greenhill, who had been my manager back in the folkie days, also managed Gary Davis. He sat Gary down and asked. "What songs did you write?" Aside from the "Star Spangled Banner" and maybe "Moonlight Becomes You," it was every song that anybody heard of, Gary Davis wrote.

Reverend Gary Davis also claimed authorship of Blind Boy Fuller's "Step It Up And Go," covered by Dylan on "Good As I Been To You," 1992.