We have a similar bird where we hunt, and we named him Einstein.
If we get a couple of birds to gobble we will work another bird 1st, if he is the only one we hear, then we try him. Has not worked so far, going on the 4Th year.
If you really want to kill the Boss Gobbler, I would say hunt one of the other birds that you said you neglected to hunt him, early until around 10:00.
After the early morning hunt, sneak into the area of the big boy and try to work him after he is done with the hens.
Have you seen him? Is it that good of a bird? Or as it become PERSONAL?