Sorry, the capstan belt is correct, my memory was messed up. The other belt will be looped onto the flywheel (the one with that the flat belt wraps almost all the way around). Towards the center, you will see a pulley. You may have to pull out the flywheel a bit in order to see it. That 3rd belt is driven by that pulley and wraps around the 2 black pulleys. Go back and watch the video again with the cracked gear. Look closely, you'll see where your missing belt is driving those black pulleys. I think I may have a spare of that third belt, PM me if you are interested in it.