10 inch Drum Brake Backing/Dust Shields

I am going to install a 7-1/4 Sure Grip in my 65 Dart GT Charger clone. It will have the Small Bolt Pattern axles. The differential currently has the 9 inch drum brakes, but I will be converting this, using a set of 10 inch drums, shoes, and the hardware, which I already have, for this differential. Does anyone manufacture/sell the 10 inch backing plates/Dust Shields for this differential? Thanks for the ongoing help on my 65 Dart Project. Much appreciated. Old Dart 66