I found a pair of Polished Stainless Steel rear fenders on Ebay. They are 37" diameter, more or less, depending how much you stretch them, and 21" wide. My tire size is 8.25x20 and this size fender fits them perfectly. They are in the pricey range, about $200 as I remember.
http://www.mrchevynut.com/100_2783.JPG
http://www.mrchevynut.com/100_2784.JPG

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