Chances are that you toasted the new Master by Letting the pedal go all the way to the floor. Always put a block of wood under the brake pedal stopping it at the most 1/2 way when bleeding. I would bet your problem is the proportioning valve but may as well get a new master again too and hoses. If the adjusters are not adjusted way far out then the Drums aren't too far gone. With new shoes, there should only be about 1/4 of threads showing on the adjusters. If you're seeing like an inch or more of threads then that indicates drums are reaching the end of serviceability.