Mattax, Thanks for the pictures, and the link to your 2020 post listing rotor vendors, very comprehensive. I wonder if any of the listed rotors are still available. These recent posts have been very enlightening. I went though some old parts I've got and came up with a pair of correct, but old rusted rotors, worn beyond use, and it turns out they were rough cast hats too. I'm pretty sure I got them at a swap meet about 20 years ago with the calipers, backing plates and spindles. I'm getting the impression that the machined hat rotors are a fairly recent offering.