OK, here is my $0.02. From what I see in the picture, I can only imagine what the rest of the braking system might look like. The wheel cylinders may be shot inside and ready to blow out. The brake hoses could be collapsed on the inside and unsafe. The steel brake lines could be badly rusted on the inside and ready to blow out with a pinhole (or bigger) leak. The inside of the master cylinder could be shot and ready to blow out also. My point is that even if you pulled the drums and things looked more or less OK, There could be a lot of damage you can't see. From that picture, I think I'd do a COMPLETE brake job.
