Hopefully @casportpony can chime in.
I still don't know much about diseases in Turkeys. Chickens are my gig.
A quick search though - a bad odor, it's possible he has Wet Form of Fowl Pox, but looking at Turkey diseases and some of the symptoms, I would research Bordellosis (Turkey Coryza) as...
I don't know much of anything about Turkeys, so let's tag in some folks that may know more about them like @R2elk @M-H-Fielding @Huntmaster @casportpony
Let me ask some questions though that may help the others. Does he have any mucous, lesions, yellow or white pasty material inside his beak...