From the Preface to the New Edition:
Black Blade Publishing is very pleased to bring Rob Kuntz's adventure, The Original Bottle City back into print.
This new printing corrects errata from the first edition published by Pied Piper Publishing in 2007, and provides a more complete gaming experience by providing statistics for many NPCs and monsters encountered in the dungeon level that were not fully-fleshed-out in the first edition. Hit points have been proportionally increased to reflect d8 HD for monsters instead of d6 monster HD, and to use class-based HD instead of d6 HD for NPCs. In all other respects, this edition is identical to the version published by Pied Piper.
Includes two separate double page maps which together form the original map of the dungeon level from 1974.