One of the nice things about those Shel Silverstein songs is that they're so easy to play....simple melodies and chords.

PAUL;   A D-G-A-D sequence....changes every bar except sometimes the last D is held for 2 bars. \


BOTTOMLESS WELL:

Intro: A (hold it) to D
       A                A7
       &                D

Main song:
D A
A D
D D7 G
A7 D

Hope that helps.