So... here's my line of logic that might be stupid.
I can't detect that the hubs are loose by the standard means of rocking the wheel back and forth in the air.
My brakes work fine, but... since adjusting the rear drums, the pedal travels about 2x as far as it used to before the brakes engage as normal. Again, once they engage, they are normal.
If I pump it once, the pedal will travel the "normal" distance before engaging. But multiple pumps of the pedal don't cause it to get more stiff. And if I hold it hard, there is no fade.
Adding this to the fact that I get brake squeak while driving that goes away with a slight tap on the pedal, I think it is not the hubs, but the calipers.
Follow? Any problem with this theory?