Tom is alive and well. This website has lyrics to many of his songs https://tomlehrersongs.com/ and a statement from Lehrer:
I, Tom Lehrer, and the Tom Lehrer Trust 2000, hereby grant the following permission:
All the lyrics on this website, whether published or unpublished, copyrighted or uncopyrighted, may be downloaded and used in any manner whatsoever, without requiring any further permission from me or any payment to me or to anyone else.
It makes a fellow proud to be a Lehrer fan.