I found some on Wheel Vintiques site. Very pricey but 15 x 4 wheel on a 5 x 4 bolt pattern. I have the same company steelies on the rear but 15 x 8 on a 5 x 4.5 pattern so it shouls look good with the poverty caps all around.
If wheel vintiques make em, I'd check if they can be bought thru jegs or Summit, or one of the other specialty wheel retailers. Maybe save a buck or two.