Officially I would do what I do with the cats here that look like Maine Coons - we call them Georgia Coons. Yes, medium length hair, big pointy ears, what's not to love? So add your own state (your location is not yet in your profile) and call him one of those!
Thats what I would do, because it's cute, but you could always call him a Maine Coon Mix or just a domestic medium hair tuxedo. If you were entering him in a household pet show class, you would have to use the last description. The first picture is my Georgia Coon Cat, Coonie (RIP) and the bottom picture is of my friends' two Vermont Coon Cats, Monty and Beastie.