Much Eroded Old Cast Metal Submarine

I have no idea the original maker of this submarine, cast iron it seems, but it certainly looks ancient now, and as if it has been long lost at sea! I love it for precisely that reason, and for the fin at what I guess is the top looking rather like a tsunami. This feels like the sort of  thing that should give rise to a novel or a screenplay, so evocative and with a bit of an eeriness about it, as if dug up post apocalypse.

4 5/8” l x 1 3/4” t x 1 1/4” w. Stable and structurally sound and sits up perfectly on its bottom fin.