Have an opportunity to pick up a floor standing unit. AEOLIAN-VOCALION, style 510 or 310, model 111155 and the serial 310-1 I wasn't able to find too much on it on the internet, and my limited books did not have it listed. Is this especially rare or valuable? Condition is OK, and original, and is supposed to have all pieces. I have not seen it in person as it is 2 hours away. Asking price is $150. Thoughts?