Have you looked into a potential different structure with instead of a seller note, structure it through equity in an LLC partnership? 

We then transferred title of the property to our business/LLC. 

We have a capital LLC just for the purpose of lending.  

He owns the properties outright, has them in one LLC, and is concerned about a hefty tax bill in the year of sale. 

After 3 weeks they said that the address of our LLC was the issue. 

Bank accounts for each and handling everything separately So, I met with a CPA last week, and the advice she gave me was to create a Holdings LLC and a Property Management LLC in addition to the current 2 property LLC's.  

I'd rather not tap into my own homes equity as I want everything to run through our LLC. 

If we can find the owners’ contact info (LLC), what if we ask them?

I did a private lending , borrower bought house under the name of LLC, first lien recorded. value of house is at least to cover the loan(as of now).

Not bad but need to be sure its worth it to rent out to people, get and pay for LLC for liability purposes, and minimize your personal use stay at the shore for 14 days?