I only investigated Fountain Head for you briefly. The "secret" discovery is that wasn't an open market arms-length transaction. It looks to me but don't hold me to it, that it was simple an exchange of remaining ownership from one person to a former spouse or business partner. The "buyer" was actually a partner (joint tenancy) of that property before she became the sole owner of it. That looks to the public as a normal free-market sale but the story behind it isn't. It looks like "seller" just gave her full title for the consideration of $76k. That is likely a similar case for the other properties you mentioned.