Dominic, I would door knock a handful of the owners in the area, and simply ask them what would be relevant to their lives on a recurring letter.

I had been given a pre-approval letter after providing a verbal app with one of their loan originators.

I sent out a lease renewal letter and I just heard back from the tenants this afternoon.  

Make the letters very short w/o any threats or formalities e.g.

Someone who knows your business and who will be loyal due to the amount of work you provide, and can assist you with evictions as well as other matters (zoning, contracts, small claims suits, general advice, sending threatening letters to people you don't like, etc.).

I sent the appeal with a copy of the sales contract and appraisal, and they simply sent me back a letter saying they dropped it to my requested value of 80k.

That doesn't mean you are necessarily going to kick them out, but they need to know that if rent is late, you're calling to ask about it, sending them a demand letter, and promptly filing an eviction.  

This deal was first constructed by driving for dollars and sending out letters by hand.

Ask the neighbors, leave a note on the door, look up the probate records if there are any and contact the attorney and the executor....look up obituary and skip trace the relatives, send a letter to the property and see if it gets forwarded to anyone.  

Hand written letters have been truly effective for me. 10% response rate.