I assume that, since they are indeed public records, like any public records, someone can enter into the county office and pay a set fee to have a duplicate made of such a record and also pay to have it certified under county seal to make it official.

When California switched to a General Index, we eliminated the need to maintain separate sets of "Book of Miscellaneous Records" / "Book of Chattel Mortgages" / "Book of Lis Pendens" / "Book of Deeds" etc etc etc

However, I have had to research 1800's Book of Miscellaneous Records for title matters in the past.  If these California books are anything like those in your area, and I believe that they are, then these records could easily be title-affecting matters.

What sort of index is maintained on such records?  I assume that the designated Guardian of Records or equivalent legal appointee (usually the elected Clerk-Recorder for a County), would bear the sworn, bonded duty to ensure that proper records are kept and that they are indexed in an appropriate manner.

Interesting, still.