In a separate unrelated email, copied to myself, Michael Gouby writes:
"In 1806 to 1861 100’s of dies had the legend letters and numerals re-punched so as to keep the die going. An entire book could be filled if one were to record every minor off-set letter or numeral re-punch of that period. It neither add nor detracts value from the coin and are not recorded for that reason".
I don't collect such occurrences myself but, if it gets more people interested in the subject, am happy that people share their examples.