I have those exact same rims on my Willys garage art. They fit fine over a D44 hub, but they don't have a tapered seat for the lugnut. I swapped to 12mm studs to match the rear Toy axle, and use factory Toy shouldered lugnuts on them. (I'd assume you can buy the proper shouldered lugnuts aftermarket in various threads too)
Without measuring, the backspacing is fairly deep....I'd guess 4.75"-ish.