Thread size on the source line is 7/16 x 24 NS (national special).
Jeff, not to get off trail, but the first picture you provided has what I normally consider a 65-66 brake pad retainer (one large piece), whereas the last picture has what I consider the 67 style, two independent smaller retainers. Do you concur, is that a slam dunk observation, or do I need to start a different thread? I guess my post started with threads and ended the same.
Thanks, John