Not a manual person but found this on the bay incase some other are interested. There are some rare ones listed. This guy has a few lots for sale
http://www.ebay.ca/itm/ATARI-2600-INSTRUCTION-GAME-BOOK-MANUALS-VERY-RARE-LETTER-S-LOT-2-PHOTOS-/262301145583?hash=item3d125dd9ef:g:k20AAOSwzgRWyfod