Checked around. Gunther's is my normal machine shop but, he doesn't have a plate. Baltimore Mack can do it, but they're really pricey. Harshman's can do it for a decent price, probably leaning that way.
Since I've got a mill, I'm also considering buying plate stock and making a Torque Plate. Looks like I can machine the plate, hone the engine and make a few bucks in selling the plate afterwards. Not sure though. Steel is cheap, but heavy. Aluminum would cut machine time, be a lot lighter, but cost 3 times as much.