Dividends were paid from the get go, but changes in the economy affected the valuations. 

This could have changed in the last few weeks and is only for Los Angeles county. 

There was a glut in wineries not long back when The Australian dollar was high and people who once couldn't get enough of Australian wine suddenly turned back to relatively cheaper and more fancy sounding French and Italian plonk, combined with the change in regulation in the Chinese wine market that killed it as a business drink.

I'd go ahead and list it.There are many past posts on how to improve your search list placement such as making frequent changes to listing and updating pictures.

Your story about the seller financing deal is powerful—trust really can change everything.

I've been managing for 15 years and have helped a couple owners change/expand their portfolio. 

Increase time spent conversing with each lead that you get to learn more about how they view the property and implement reasonable changes accordingly.

Second, there's a legal concept called "unjust enrichment."

However I'm thinking if I ever hit the windfall on something like this, their pockets are probably way deeper than mine and I'm not going to want to spend the money to fight it.

I don't know how we would ever prove, to their satisfaction, the above.