This one is a keeper and was not hard to build.
The body consists of two main parts a 4.5 inch diameter pipe, 33 inches long for the riser and a 6 by 4 inch piece of RHS, 20 inches long as the burn chamber.
The pellet hopper was 3inch by 3 inch stainless steel SHS, 14 inches long. The pellet burner was 5 inches deep, leaving an inch at the bottom of the burn chamber for air flow. The secondary air intake inside the pellet hopper is 1.5 inches by 2 inches in width and depth and went the full length of the hopper which was 14 inches. Hopefully with all these dimensions and the video, you should be able to reproduce this.
I had a lot of fun making this, and I hope you have fun watching it.