A combo screwdriver and flint knapper plus a knapping awl
Those look easy enough to make with a limited amount of tools or experience. A person could make something like the screwdriver knapping tool from an old worn out screwdriver, then put a bend in it for leverage and cut off or remove the handle, then file or grind out the knapping notch.
Good luck to anyone who gives it a try. If you do it post a picture!