The Making of a Market shouldn't require anything other than the preceding quests in the chain to be completed as you said you did. He should standing in front of the central fountain looking toward the Mendicant's Court area if I remember correctly.

Sometimes when needed NPCs don't appear and you've met requirements for a quest, exiting then restarting the game will reset whatever has gone wrong and they will be where they should be. Give that a try (if the problem hasn't already resolved itself). If it doesn't work, let us know and we can try to think of other solutions.