Ouch.
I am going to disagree and say that the
parts are toast and the winch is probably toast. Find and image of a new winch and you will see just how severe the wear is. At a minimum, the gears need replaced.
The other concern is the pawl socket. The pawl can come out, jamming the winch, or jam in place, allowing the winch to spin backwards. Wrists have been broken this way. The center spindle, bearings, and pawls need replaced.
We can be certain there are additional worn parts. This winch has been very poorly maintained, and I would guess that every part is damaged. The parts will cost as much as the winch.
It is a
safety hazard. I am an advanced cheapskate and I doubt I would try to fix it. Sorry.