PROBLEM cdw drywll

I am a condo owner in FL. Apparently in 2000, 2001 Chinese drywall (CDW) was used in building our place. Only a small number of the boards were CDW.
We have varying amounts of tarnishing on cooper wires, etc in the different units. We can find the CDW. No evidence of tarnishing can be found around some CDW boards, while others are likely causing varying amounts of tarnishing. We and others have lived there for 15 years with no apparent ill effects or functional problems with wiring or appliances. But, the word is out and people feel we must prove we have no problem drywall to restore our property value. Unless we can do selective drywall replacement, the cost to recover the value will be as much as can be gained.

My question is what are the standards to use to decide which board to remove? Can you identify someone I can discuss this with?

Thank you for any help you can provide.

David Redmond
Vero Beach FL
401 524 0645