Hi JD.  I have a collection of harmonics and tutorials that I do nothing with.  Another harmonica player to search on YT is Brendon Powers.  

Neat, mate! I can play the 123 draw notes on a blues band harp You can get one here https://www.hohner.de/en/instruments/harmonicas/diatonic/enthusiast/blues-band

Here, this is not whistle, but it is exceptionally impressive.

Buddy Greene - Classical Harmonica Medley (Live) - YouTube