Are you for real ?????? Having a bad or broken solder joint will affect the value even more. Also if it has been resoldered somewhere in the '80's or '90's I dare anyone to spot the difference with an original solder joint after 5 years or short of investigating it with an electron microscope and a chemical analysis of the solder. Which would damage the original solder joints. I've just about had it with all the BS that is being told around guitars, amps and effects. And the people that perpetuate it by repeating it time and time over without thinking. If you replace the original 1M pots and keep them and nut them back in when / if you sell the guitar what would be the problem?