I have a 1969 Silvertone acoustic guitar. I found it in my basement. I checked it over. It holds tune pretty well and there appears to be nothing wrong with it - with the exception of the neck. Its coming off the body (sorry, I don't know much about guitars, so I can't be technical). The neck it not totally off the body, but there is a little space between the base of the neck and the body that's about three centimeters in. Its wide enough to slide a piece of paper through. Is this worth getting fixed? Does the guitar have any value?
Oh- the condition of my basement (where I found the guitar) isn't wonderful for instruments, but it is better then some. Its not terribly humid, but not dry. Its never too cold and never too hot.
I've never heard of necks falling off, but is the rod in place? I don't know the technical term, but there should be a rod running through the neck of a two piece guitar. If the neck was glued then it's probably not worth it. Also check to see if the neck is bowing. The rod controls how far off the strings are from the fretboard. If the strings are touching and making a buzzing should when playing, and you can't get it fixed, than you have a problem. (I dunno if that was much help or not)
Is there a way to stop the crack from speading? Like some kind of glue? I don't mean to sound like someone who misstreats there expensive instruments becuase I work very hard to keep my piano, violin, and cello in good condion.