If the birds are consistently doing the same thing, you could simply get there while it is still dark, not set up any decoys, not touch a call, and wait for them to come by you. Simply be in the way of that gobbler getting to where he wants to go. If you want to use some decoys, fine. As far as calls, I'd wait to see if he gobbled from the roost, and then throw some light, almost muffled yelps at him. A few purrs, a few clucks, and wait. Don't call too loud. Just let him know that you are there. Again, the key is to be between where he is, and where he wants to go. Do that, and we'll be looking at pictures next week.