I still am thinking that with that adjuster completely closed (not expanding the brake shoes at all) must be why the old pads aren't worn at all, except for about 1 1/2" at the ends of the 4 pads.
That's caused by running standard radius lining in an oversized drum. They will only contact at the ends, and take a long time to "wear in" to full contact with the drum. Use water-based glue to attach a piece of coarse sandpaper to the inside of the drum, and scuff the new linings back and forth to match the radius. Once that's done, use boiling water to remove the sandpaper from the drum. Then buy a crash helmet- - - -if you stomp the brakes like you used to, you'll bounce your head off the windshield!
Jerry