1992 Dual wheels Ambulance package?

I am trying to locate a set of 4 or 5 wheels from which I think came from a 1992 or newer Ford E350 Van possably a Ambulance. The ones I have are chrome centers with painted rims. They have 8 round cooling holes and 8 lugs with lug holes coined in and out to lock together. These rims use the lug holes to center the wheels on the hub. I have 2 and need more. I converted my older ford motorhome class C chassis from 16.5 to 16 wheel with new tires and 4 of the wheeels i got wont center because they are flat mounting and use the center of the hub to center the rim.