Sudy, There is a book on Thomas Elf: Thomas Elf Cabinetmaker by Samuel A. Humphrey. It was published by Wyrick & Company, Box 89, Charleston, SC, 29402. ISBN 0-941711-15-3.
I had the good fortune to spend a day in Charleston with Humphrey, a retired Navy engineer. A most interesting day. He has done a lot of research on Elf. He spent a lot of time trying to document some of the pieces attributed to Elf, which was difficult and contoversial since Elf never signed any of his work. Humphrey has sinced moved away from Charleston.
I made a reproduction of the Rutledge Family Breakfast Table, plans for which are in Humphrey's book. A picture of mine is in the SAPFM Gallery. If I can furnish additional info email me outside the forum.
If you have a problem finding the "Thomas Elfe- Cabinetmaker" book by Samuel A. Humphrey, There is a Half Price Book store around the corner from my home that has five new copies. I think it is about $10.00 plus whatever mailing cost are involved. E-mail me off forum if you need me to get it for you.
All of the printed references to your cabinet maker have his last name spelled Elfe. A quick search of Google yields quite a bit of info. http://www.google.com/search?q=%22Thomas+Elfe%22&btnG=Search&hl=en&ie=ISO-8859-1
I hope you find what you are looking for. If not, check back.