WHY would one NOT record their deed? If UNRECORDED, any liens, judgments, etc, filed against the PRIOR owner attach to the real estate. If the "prior owner" had entered a nursing home, for example, the entire amt still owed would be IN FRONT of your interest. Not recording a deed is a crazy risk! The whole POINT of public records is to make deeds thAT BURN UP IN FIRES AND SUCH unnecessary.
Your only option is to track down the seller, if alive, and hope they are
a. capable of and willing to create a duplicate deed
C. Able to convey "good" title.