I just became aware that Marc Miller and Far Future Enterprise has just placed the original Traveller Book on RPGNow as a print on demand book. Just ordered a copy as mine is battered to hell and back. I will post about the quality of the book when it comes.
As a bit of history Classic Traveller came in three forms.
The original boxed set with Book 1 (characters), Book 2 (Starships), Book 3 (Worlds)
Starter Traveller (free on RPGNow)
and finally a hardcover Traveller Book.
The Traveller Book became my primary Traveller reference and has seen much use over the years.