while facing similar callenges from wary toms, I've found that my deer hunting patience has worked wonders.
1. Don't give up on this bird, pattern him instead. He may not do the same thing everyday, but he will do the samething multiple times. Enter the field, or walk by a log or rock pile, something will be his weak link.
2. This is where your deer hunting will pay off, you will probably spend a few days just sitting and enjoying nature, than it will happen, and the ol' tom will come strolling by. You've done it for deer,and never thought twice about it, try it for tom, and bush wackem' on the way by.
3. No calls, no fakes, and quiet, early, entry.
4. and a little good luck never hurts either.