I know someone selling a wonderful old { early to mid 60's } Gibson 12 string - a B45-12N. I've heard it played on many occasions and I know it has a wonderful sound. The owner is willing to sell it because it's been sitting in his closet for several years and it hasn't been played. The case has some mildew on the surface - front and back. And it looks as if there is some mildew on the fretboard as well. The interior of the guitar and the body appear to be free of mildew. So my questions are:

How do you remove the mildew from the fretboard of the guitar ?
Will it keep coming back?
Do I need to get rid of the guitar case ?

The case is not the right size { too big } and the wrong brand { Guild } so I have no problem getting rid of it - I don't want the problem to spread to my other instruments. I'd just as soon get a new case that fit it better.

Not buying this 12 string is not an option. It sounds too good. Soundwise it's the best 12 string I ever played. It has a few dings on it - but then again so do I.