I posted the first query because I was making an article for our local genealogical society newsletter for Spring 2003. At that time I located a contact: Rev. Frederick Pyne, Registrar-General DSDI, 3137 Periwinkle Court, Adamstown, MD 21710-9649 Email:
FrederickPyne@cs.com He stated there were about 900 members then and that the fee's for applications were $40.00 which included the 1st years membership.
Mr. Pyne spoke of the society's recent publication, a series of 7 volumes, "The Genealogical Register of the Descendants of the Signers of the Declaration of Independence, Picton Press, Rockville, ME, (1997-2002) It covers from the Signers down through about 5 generations of descendants.
Mr. Pyne also stated the purpose of the Society is : "To honor the signers, help to maintain their homes and grave sites, and keep their places of work and living in memory. To encourage scholarship and provide for scholarships to persons seeking both undergraduate and graduate degrees."
To join, you will need to document your lineage from yourself to one of the Signers and you may use the above series of books.
I have had no further up-dates since the Spring of 2003. Hope this helps answer some of your questions. J. A. Childers