Welcome, Joe.
I'm no expert, but the crackling pot sounds like you need to do the 'exercise pot' maneuver. If you rotate the pot 50ish times through the entire range (off to full on) in a quick fashion, that will often work out any crackles in the sealed pots. (
http://club.alembic.com/Images/16271/16357.html?1107712343)
Also- have you checked to make sure that the washer and nut on the inside of the electronics cavity is snug? After 20 years, the wood compresses a bit and it's not unusual to have that nut loosen just a bit. If that happens, the volume pot can spin a bit- possibly causing something to hit the shielding and shorting out.
Those are just my guesses? I'm sure some more informed opinions will drop in before long.
(Message edited by tbrannon on April 12, 2015)