Re: What kind of cleat is this?
I don't think I'd trust a loop through the chocks.
Perhaps back in the day they tied the bow line to the handle, although then the line runs "backwards" to the chocks. Without a windshiled I might expect a cleat on the center of the dash, so you don't have to climb out on the deck.
I wonder if there was a cleat in there somewhere, or the horn or light was added and replaced the cleat (not a good idea IMO). I've seen bow lights that are supposed to act as chocks (also not a good idea) so maybe the horn or light/flag assembly served like a tow head.