I use RealQuest which is put out by First American for the asset industry. They advertise that they include 98% of all MLS listed properties and 75% of all non-mls private sales. I suppose they are linked into court house records to get the latter.
You can also subscribe to Realquest for about $0.40 per property search. I only use it to verify info of properties that I work on outside my local mls coverage.
Before I would included them, I would ask them to email you the RealQuest data sheet for your consideration to include and records.
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