I finally discovered that you have a list of serial numbers on this site. I found that my dad's Martin alto was made between 5-1-23 to 1-1-24. It has not been played since the mid-50's (when I was a sophomore in high school) and has had no maintenance since then. I'm sure that all of the key pads and the cork on the neck need replacing. I also needs polishing. If I don't have any work done on it, does anyone have any idea what it would sell for? If I do have the necessary things done to make it playable again, how much more would it be worth? Thanks in advance to anyone who can give me some info. Janie