i bought some plastic 309 plates for my dearborn. had to use a jigsaw to enlarge the inside diamter of the ford plate by 3/16" so it would fit in my planter. every dearborn plate i've seen is metal. if you can weld and use a grinder, and have a ford plate for a pattern, you can probably convert a dearborn plate to fit a ford in about 30-45 minutes. i really doubt you'll find dearborn plates though, ford bought them in the 50's and changed the inside diamter of the plates when they started producing them.