The novel methods, apparatus and reworked rotary braking surface product, for example those exhibited on interior cylindrical braking surfaces of a cast iron brake drum, serve to replace manufacturing defects exhibiting residual tensile stresses and outwardly directed tool marks with smooth compressed braking surfaces in a final manufacturing stage. The through hole has a horn-shaped opening formed in continuation of the through hole at the rear acoustic terminal side thereof such that an inner diameter of the horn-shaped opening is increased toward the rear acoustic terminal side. The imaging path provides for transmission of one or more fluorescent emission signals derived from one or more samples in the at least one chamber of the at least one microfluidic device.