The Single Axle Trailer Fender w/ Backing Plate # HP97FR has the backing plate tack-welded to it.
If you'd rather add your own backing plate then you'll want to go with the Single Axle Trailer Fender for Enclosed Trailer # HP37FR which is the exact same thing, just without the backing plate. view full answer...
I believe I have something that will work for you, but the Curt Hitch Ball # 40038 that you referenced is not made in the USA, it is made in China.
You might be interested in a Convert-A-Ball Interchangeable Ball Set # 904B. This product is made in the USA and comes with an interchangeable hitch ball that will give you the option to easily change between a 2 inch and a 2-5/16 inch ball. view full answer...
The Chrome Plated Clearance Light # MC81AB is made of plastic. It does have a metal backing plate in order to ground the light through the hardware. view full answer...
I spoke with my contact over at Kodiak and he said that the stainless steel disc brake kits that they carry are completely stainless steel. That does include the backing plates for the pads. view full answer...