[Oldtix]

Last summer, I read David McCullough's excellent biography Truman...a lengthy but very enjoyable review of his personal and political life.

As I recall, Truman reportedly dedicated many hours daily to personally answering his correspondence. He was of the old school that considered it good manners, and his writings provide an exceptional record of his presidency. He would have certainly taken the signing of condolence letters very seriously (particularly so near the start of his term in office), so I wouldn't dismiss the possibility too quickly. Not saying it's real...I'm no expert...but it's more likely for Truman than for later presidents.