Spread 4 slices of bread with the mustard and 4 slices with the Russian dressing.
Dividing evenly, top the mustard-spread slices with the turkey, sauerkraut, and cheese, then the remaining bread.
Heat the oil in a large skillet over medium heat.
Add the sandwiches and cook, pressing occasionally with the back of a spatula until the bread is golden brown and crisp and the cheese is melted, 3 to 4 minutes per side. Serve with the potato chips and pickles.