Sometimes you get lucky.You could even bring up the subject of seller financing (search online for ideas of how to structure a seller financed offer), and make sure a competent real estate attorney helps write the offer documents (if it gets that far). 

If the proper reports and documentation are not completed, you run the risk of failing an IRS audit and the cost segregation not being honored.

We work closely with the listing agent to get documentation and we start making aggressive, contingent offers on replacement properties as soon as the inspection contingency closes on the sale. 

@Victor YangWhy are you not reaching out to a NC real estate attorney to draw up a document that spells out the agreement that you are looking to do with the tenant?

What documents do they require, what credit scores do they allow, how do they verify previous rental history, etc.?

https://www.biggerpockets.com/...12 Frequently Asked Questions (And Answers) About DSCR Loanshttps://www.biggerpockets.com/...8 More Commonly Asked Questions and Answers to DSCR Loanshttps://www.biggerpockets.com/blog/eight-questions-and-answe...What Documents Do You Need for a DSCR Loan?

The document that records the sale is called a "Tohon" and does not list a sale price. 

Improvements that DON’T drive the ARV as much: Windows, Landscaping, Driveway, Rough Plumbing & ElectricalI agree with @Jaron Walling about meeting the appraiser at the property and providing documentation.

Seeing as they are the owners I would think their name would be on those documents.

Promissory notes are transferred by endorsing the back or a document called an allonge.