Send them notice of balance due, file collections, and sue them in small claims court. 

First, as for the state of Florida, lease agreements can only be created by attorneys, except for Supreme Court approved standard leases in your state.

I spent about 35K fixing it up and was all in about 50K with taxes and court costs etc. 

The best I can offer is to tell you to verify that income carefully, and as @Brent Paul said, make sure that income is not about to be interrupted.Sometimes with CC debt, you do run across reasonably smart, stable, functional people with that much.

This is the problem with taking payment for the last month when a lease can extend indefinitely.This arrangement is illegal in PA due to a court decision 10+ years ago.

I have seen some people tell the owners that they can rent it after they sell it but if they did not make payments to own it why would they pay rent and you will simply be heading to court to evict them. 

The kitchen is not about pure function any longer, it is a piece of art all on it's own.

I’m also wondering if it’s a function of business structure.

I ended up with a court ordered eviction.

The key here is provable in court.