Just get some large “R”clips and push them all the way through until they’re hanging, brush and limbs are not gonna pull them out, been using them this way all my life
Work the winch cable under the bucket, then attach to the tractor, tie the loader lever back as if to raise the loader, as the cable tightens to pull the tractor, it will also raise the bucket enough to load.
You don’t happen to have a piece of the cross drive bolt still in there? And or the hole may have a “burr” from the bolt hammering on the shaft, I’d try to align the holes to be sure the hole is clear, then I’d cut some wooden wedges to hammer on each side behind the sprocket to bring it out