Greetings,
Back in the late 80's and early 90's Ford Motorsport catalog listed the 4 Bolt 15 X 7 Steel wheel that were used in the Mustang Police pursuit vehicle. It had multiple verticle oval shaped holes in the center section. The early CHP Mustang actually had wheels that used Pinto design centers and much skinnier tires, but the CHP were having trouble keeping the cars on the road. Later they went to alloys like the Mustang GT , and Turbo coupe used.
Those later Steel wheels could be just what your looking for..
Update: from the 1987 SVO, motorsport catalog P/N M-1007-D157 , the web site won't allow the image to be attached.
Cheers,
Pintosopher