Slice the bread in half lengthwise. Spread one half with mayonnaise and the other with mustard. Layer the ham and Swiss cheese on 1 half of the bread. Layer the pickle slices over the cheese. Top with the other bread half. In a large skillet over medium-high heat, heat enough butter to coat the cooking surface. Place the sandwich in the pan and weight with another heavy pan or a brick wrapped in foil and grill until the cheese is melted. Cut the loaf to make 4 sandwiches.