His family members tracked him down and I got a notarized signature.

Probably the only way would be their rider laden renters insurance to cover an accident(s) along with a notarized document removing you from all liability from the beginning of time until the next millennium. 

Our long time sole master plumber gave us a notarized letter stating that our plumbing is sound and no repairs were done in our home during this billing period.

Talk to your realtor to find out if having a notarized copy of the lease would help. 

Seller wants to keep his mortgage in place and take payments from me with a notarized promissory note.

To put a property under contract in Germany, only a notarized agreement is binding.

This includes a notarized letter from a healthcare provider, which you mentioned in your post.

We used a notarized Bill of Sale and Promissory Note.

So make sure you have every 'I' dotted and 'T' crossed (if you are the listing agent that means that you need a drivers license, copy of the listing agreement and perhaps a notarized letter from the seller).I'm surprised that with a complete rehab needed, you didn't have the buyer be responsible for the CO.

Copy of the original loan doc that stated no pre payment penalty.and a notarized letter with witness's as to what was in the mailer and the account this was paying off, along with account number on check of course.