Bread-Bakers v101.n004.5

When I was young (about 60 years ago) we would buy Polish Rye or Sour Rye
bread. It was more sour than Jewish rye and no caraway seeds. The crust was
hard, about the same hardness as an egg shell  (well, almost)  and looked
crackly, like aligators skin. Anyone have a recipe, or know where I can buy
some?