Can bank foreclose on lien that is past SOL? (x-post)

[stevet1]

What is the name of your state?PA

My dad was ripped off in late 1970's. He bought a piece of land in the Poconos through some unscrupulous bank. He paid off the mortgage, but has no records to prove it other than the bank sent him back the original loan paper. He never received the deed to the land. He has moved several times since then and has lost his records of payment of the loan.

Fast forward 24-25 years. No action/notice from the bank. The bank has been bought out by Wachovia many years ago. No action or notice about any unpaid loan from Wachovia either. My dad has discovered that the land is worthless (not buildable on) and tried to donate it to the local homeowner's association. A title search found that Wachovia has a lien on the property for the entire original loan amount, as if it had never been paid. (I suspect that the unscrupulous bank sold itself to Wachovia, falsely claiming these paid off loans as unpaid) Now Wachovia is trying to foreclose on the property, and mentioned that it may sue to try to collect the old debt.

Several Questions:
1. Can we stop Wachovia from foreclosing based on SOL? If so, how can we stop Wachovia.
2. We actually don't want the worthless land, should we just let Wachovia foreclose anyway?
3. Can Wachovia sue my dad for a lien 24+ years old?
4. Can Wachovia do anything that can harm my dad's credit at this point in time?