Do you make a fully threaded stoprod or only use end threading?
My standard length Stop Rods are threaded to require only one stop nut and offer a generous throw to reach the low “Pedal F” using only your third slide. However, I can make a fully threaded stop rod for you as a special order item. It requires two stop nuts to lock against each other (like the Bach system) and offers a shorter throw. With a fully threaded stop rod, you may have to use your first valve slide in conjunction with your third valve slide to reach a “Pedal F”.