Just letting you know straight up about the amount of useful responses coming your way.
You are asking about the Holy Grail of turkey call making secrets. Marvin took a TON of heat for making that tutorial. So, your best bet is going to be asking specific questions on your issues as you go, or find someone to teach you the ways.
I may be surprised, but I doubt many folks come out of woodwork to lay down many more trumpet secrets than have already been shared on this forum.