This Avalon Hill reference CD has everything you need to make your game playable! -
Game Rules in PDF format - 1961a, 1961b, 1965, 1977
Game charts, log pads, counters, and replacement counters.
A map of the game board
A PDF with Avalon Hill General magazine articles in it! 134 pages!
Bonus - the entire 1991 Smithsonian version of the game is included too!
This is a very nice to have addition for the game with scenarios, variant counters, and additional rules, commentary, and discussion.
The free book link below is to a US Army historical site with archival material.