Rule of thumb for a yacht mast – 150% hull length. So 1.9 metres tall. Or about 6 feet.
In old money, it is about 50 inches long, so "could" be an old Marblehead, or based on one. Before radios were mainstream, racers were solidly built and carried a vane for steering and had a shallow heavy fin. With radios came the lightweight construction and long fins. Not 100% sure which was first.
Currently, there are the Canterbury and Nottingham J class, which are 50" long, weigh 15 pounds and carry IOM rigs and have the shallow fin weight.