Every bird and situation is unique. Try something different. Just from what you have written, I too would suggest less calling, scratch the leaves, etc. If the terrain allows, something else you might try is giving a quick series of calls, then move toward the bird as far as you can without him seeing you and set up. He's apparently figured out that not all calls are real turkeys, so he might cover enough distance to investigate, putting him in range.
The other side of the coin is to call him to death. I've seen a few birds that if you keep hammering at them with yelps and cuts, they will eventually break down and commit.