The same diameter hubcaps fits the Ford spoke wheels in 16,17 and 18 inch. Snyders has them on page A-93 part number B-1130 price $19.50 each Fits 1932 thru 35
Bob Drake has pictures in his catalog, http://www.bobdrake.com/Categories2.aspx?Id=hubbeautrin I prefer the 1932-33 4 cylinder for my application but he also has V8 and street rod versions. The same hubcap will fit 1932-35 wire wheels.