I have a Concert Keyboard Amp purchased in the late 70's (around 76-77) which was just serviced a month or so ago. The amp is in excellent working order. There is one minor cosmetic issue, one of the channel knobs (there are 3 channels) has a piece out on the side, but the knob itself works fine and the damage isn't noticable from front view. The case is in good condition. Considering the rarity of working ones in good condition, I'm asking $700.00