Making wheels is an enterprise that quickly rewards the effort of making jigs and fixtures since there are so many duplicate parts required. I have made a number of jigs for making half scale mountain howitzer wheels (don't ask for pictures because most of them are in someone else's possession, along with the wheel parts.) For making felloes, I made an adjustable center, two jigs for cutting the curves on a bandsaw, another for cutting the angles on the ends, and two for drilling the spoke holes and the dowel holes in the ends. For the spokes, I made, or designed but have not yet made, three jigs for sawing and two for the tenons on the ends, plus a special cutter to cut the tenons.
I plan to make hubs from aluminum instead of wood since the aluminum has no grain and won't need the bands to stay together (although simulated bands will be present.) Paint will hide the aluminum.