UPDATE: Not many of these winches around.
While going through some old Four Wheeler Magazines, I came across two different ads for a McCain Hub Winch. As best as I can tell, you attach it to the front hub, wind a cable or rope around it, and then start the front wheels turning, which would pull the jeep forward. Also, the February 1969 issue of Four Wheeler Magazine has an article about the winch, but the seller wants $25 for it. I’ll wait until the price drops.
This first pic is an ad for the winch:
This second pic shows an ad for Chachua’s Four Wheel Drive Center. If you see #2, you can read about the hubs:



















