Right rear sticking

X2 on new shoes and no grooves or lips in the drums.
The rubber brake line from the rear to the body can go bad and have an intermittent blockage, not allowing the brake fluid to return. I would think that it would affect both brakes, but fluid dynamics can be funny sometimes.

Also, did you adjust the axle end play by turning in the large threaded part of the axle retainer? Did you reattach the little clip under one of the five retainer bolts that keeps it from turning? An axle slopping in and out 1/16 of an inch would do weird stuff too.