Most moccasins can be sewn together with leather lacing. The holes are created where the lace will pass through. Often, the holes are made with a leather needle that cuts a small hole in the material. The lace can be made with only a few pieces of leather, each one using a lacing needle.
I’m about to make a pair after doing a lot of research regarding the regions and tribes. Most moccasins were sewn using sinew (you can buy artificial sinew and split it). These days, crafters use glover’s needles (unlike harness needles, these have sharpened points) to pierce the hides. In short, the moccasin upper is sewn to the sole and at the heel while inside-out, then turned right side-in. The vamp and upper leg section (if either are needed) are sewn after. Lacing is used to secure the moccasins to the ankle or, if they are boots, to the leg.
The early crafting styles always impress and inspire me - and I’m excited about your project, it sounds like that research will help lead to an excellent piece, while also integrating and honoring the history and heritage of the people that inspired that area of the craft.
Helpful tip on the glover’s needles, too, the right ones for the job can make a world of difference. Hoping these come out great for you