There are 3 CDs published and they all are, as far as I know, still being sold:
There is a book which contains sheet music for every song from every album
plus some extras. It has a foreword by Tom himself. It is called
Too Many Songs by Tom Lehrer, with Not Enough Drawings by Ronald Searle,
and came out in 1981. The book is published by Pantheon Books, a division of
Random House. ISBN number is 0-394-74930-8.
There's another book called the Tom Lehrer Songbook, which is (c) 1952 Crown Publisher and contains (presumably text and music for) The Hunting Song, The Irish Ballad, I Wanna Go Back to Dixie, My Home Town, When You Are Old and Gray, I Hold Your Hand In Mine, The Weiner Schnitzel Waltz, Fight Fiercely, Harvard, Be Prepared, The Old Dope Peddler, The Wild West Is Where I Want To Be, and A Christmas Carol.
Hunt these down if you have time. I have no clue what's in them.
I only have the first 3 CDs I mentioned. I got them at Tower Records in NYC. I know that on the web World Wide Music stocks them. That site also has audio clips of some of the songs which makes it definitely worth going there. I need to check on copyright laws to see if I can put these audio clips on my site too without getting sued, convicted and executed.