The hand throttle was just an option. Not tied into a PTO, winch, or anything else. Remember the Bronco was intended as a farm vehicle that could be used for going to town. So it had features of a truck in the 60s. One of which, the abality to hold a fast idle at will. More of a set the idle to cruise the pasture at desired speed or just get the engine warmed up on a cold day. We are talking days of not so great fuel quality and hand choke carburator engines. I can remember the days where my brother would drive us to school and I was tasked with starting the old Plymouth up and I could get a ride and not have to take the bus. Trying to get the engine fired up, kept running long enough to stay running on its own. The best I could hope for was the fast idle cam was working with the choke. Some days it did, other days it took a bit of teasing the engine to stay alive long enough to run without interventation. And that Plymouth was a decade newer than the Bronco. And civilized with an automatic choke. But still a 3 on the tree.