I have looked for a capstan pulley that mounts in the gooseneck ball but have not found one.
I have loaded using the gooseneck ball in the bed of the truck which works well for the first elk.
Just anchor one end to tree wrap rope around ball and tie to elk, then drive forward.
The halter on elk head might work better than a knot around neck.
Even if I have to pound in a deadman to anchor to, it is faster than quartering.