This is a real head scratcher... The coin does have some nice natural luster... But that horn. I'm going to guess 45 but wouldn't be surprised at a 50. They attribute the horn to a worn out pair of dies and a junky strike.
Any possibility that is a thin planchet? That would account for the strike. You say worn out dies, but all the details that are there seem to be pretty crisp. I think it is nearly entirely the strike.