Saddle stitching is a real bummer. Very hard on old hands. I've heard to do it correctly one needs to have needles in each hand and an awl in the right. Put the leather in a wooden leather vise. Punch with the awl, sew, sew, punch. Never letting the awl go. In modern days we have a fella in our club named Horse that does it with a drill press. He glues the pieces together, marks the holes with a tool that determines hole spacing and drills them. Then of course he does the stitching by hand. No sore hands and it looks great.
Regards
Wounded Knee