I know they are hard to find, here is a set on tbay
http://www.ebay.com/itm/1927-FORD-MODEL-T-FORD-HUB-CAPS-/141292475407?pt=Vintage _Car_Truck_Parts_Accessories&hash=item20e5b0140f
Ed, those are way uglier than the lost wax castings available in Australia. At $300 they are cheaper though. It might be interesting to see where the price ends up.
Allan from down under.