Nice write-up THANKS. I had an inner seal that was bouncing around on the drive shaft, which allowed the moly grease previously packed into the knuckle to migrate into the differential and contaminate everything. Moly is nearly impossible to remove from porous iron and steel castings, by the way. The seal was loose because the retainer was made poorly. The new seal pushed into the retainer with my thumbs, so I peened the retainer a bit to keep the seal in place. Wonder how the last guy let that go?
If you have a specific method of removing and re-installing the brake shoe return springs, or a specific tool you used for that, it would be good to post it. They are quite strong (I haven't pulled any of mine yet).