Preheat a frypan on medium to medium low heat. Butter one side of each of the slices of bread and place the buttered sides together. On one set of bread, lay a slice of swiss cheese on the bread, then top with half of the warmed corned beef, then half of the drained sauerkraut and half of the Russian dressing. Place the sandwich buttered side down in the frypan and top with another slice of cheese and the other side of the bread, buttered side up. Cover with a lid and cook until the cheese melts and the bread is golden. Flip and cook on the other side. Repeat with the makings of the other sandwich.