I ran into the same problem with the grill fasteners. Made my frames out of 3/4" MDF and 1/2" hardwood dowels for the vertical bracing (less diffraction). I then bored the cabinets and frames for the large Parts Express snap in grill fasteners. It looks great and works just fine. The inside corners of the grills have a corner brace to install the male halves. The position of the parts is determined by using the upper horn section 3/4" corner blocks where the stock 3M fastener is located. Just bore the correct size hole in the end of the blocks for the female half.