I have a 46 btn Lachenal McCaan Duet for sale. It was re-tuned to concert pitch and re-valved by the Button Box several years ago, hasn't been played much since then. I tried selling this on eBay several times and all I got was complaints about the cost.
The Button box tuner said it had a "sweet" tone, but maybe he was just being nice. It sounds better than either of my Crane duets, and I kept it for possibly spare reeds or to do my own Hayden style analysis, but lately I need the money and think it would be better off being played.
After reading Jody's comments on safe selling, I have decided to just put it up on eBay or Reverb.
Chris