Cut the sweetbreads into thick slices. Remove the rind from the bacon and stretch the rashers around the sweetbreads. Thread on to 6 skewers and cook under a medium-hot grill for 15 to 20 minutes, turning occasionally.
Fry the breadcrumbs in butter until brown and coat the sweetbreads with them. Arrange the sweetbreads on a bed of the remaining crumbs. Serve immediately.