Back before the Rat and cables, Proco made speaker cabinets. Similar in design to the EV TL series boxes, I believe that they were made of 1 in. thick particle board (yes, a full inch). I haven't seen one of these since about 1980, but recall that the 2x15 with a GK head was the most incredible sounding amp. Anybody out there use or still have a Proco speaker cabinet?