Great video Dan, I can do all that pretty well, as far as getting the high note and going to a low note but it did give me a refresher.
Positive note here: the other day I was makeing some deliveries around Nashville, had to go to Liepers Fork, Tn, and from there to Triune Tn, long drive. Had a call with me and started running it and got to experimenting with were I placed it in my mouth, found that sweet spot, I get a pretty good sound out now and clucking seems to be easier and more authentic. That gobbler yelp though is still pretty hard for me to do.