In Evidence Explained on page 35-36, Elizabeth Shown Mills talks about the analysis of public records, e.g. events which are recorded in register books. She gives an an example a church register book which appears to be an original, but might be an administrative copy. One of the clues might be that the book is all in the same penmanship where we might expect a variation in handwriting. Another is that records from an earlier date may have been copied into a form book that was not available at the time the events took place.
Are the entries recorded in a form-type book for a period in which such books were not the rule? Preprinted registers discreetly carry printing dates that may reveal their creation long after the original events occurred.
How much is known about the form books for parish registers that are used for recording baptisms, births, and deaths in England and Wales? When did they come into widespread use? Is there evidence on the pages themselves that might provide clues about when the book itself was printed? Are there different styles, and if so, how many exist?
(I have image copies of parish register pages from Devon, but I did not scroll back to the beginning of the books while I had access to the collection on Find My Past.)