A Scrabble game from the earliest period, with the 1948 copyright rules, has just appeared on the scene. I'm not aware of any other extant copy. I've incorporated the 1948 rules into my "Changes to the Scrabble Box Top Rules" page:
http://www.donaldsauter.com/scrabble-rules.htm
The 1948 rules were copyright on Dec 1 1948, and were superceded by the 1949 rules in July 1949. You can figure sets with the 1948 rules are very rare, indeed.
If a page of Scrabble rules sounds dry, give it a try; it's laced with a bunch of pithy comments.
Donald Sauter