Is there a way to determine the model (i.e. High Power, Ultra etc.), the date of manufacture and the specs (stereo/mono, watts per channel, bridgable etc.) of a "newer" (last couple years or "Electracoustic") Walter Woods amp? How many different models has he been making recently? I've looked at a bunch of pictures here on TB and on Ebay and it seems very difficult to tell one from another. Someone mentioned that all of this info is silkscreened on the bottom. Is this correct? From the pics I've seen, the only difference I can tell is the color of the lamp on the front (green , orange , red etc.). So if you buy one of these things on Ebay, how can you be sure of what you got?