If you're not smoking the corned beef, skip to the next step. If smoking the corned beef, heat your smoker to 225˚F (107°C) place the corned beef on the smoker plate, and cover the smoker. Smoke the corned beef until it reaches an internal temperature of 190˚F (88°C), approximately 6 hours. Remove it from the smoker and let it rest on a cutting board at least 15 minutes to allow the juices to settle.
Carve the corned beef against the grain into 1/4-inch-thick slices.
Slather 1 side of each slice of toast with Thousand Island dressing, then place 2 slices Swiss cheese on top. On half the bread slices, place 4 tablespoons sauerkraut and several slices corned beef.
Put the sandwiches together, then press in a panini maker for 3 to 4 minutes or cook in a skillet over medium heat, flipping once, until the toast is golden and crisp. Serve immediately.