It's worth a lot in pristine condition, according to this article with a similar description as your rarity, so it might be worth encasing to prevent any further damage. JMO.
It looks like Die Deterioration Doubling to me rather than machine doubling. Note how the doubling is a bit sloppy (uneven). ~ Chris
Isnt the first give away the MM being of similar doubling as the date? There could obviously be other things going on but when its the same or similar this flags machine correct?
its die deterioration doubling, worthless doubling, proven by the fact that the mint mark has the identical doubling as the date, which is impossible in 1968 as the mint mark was hand punched into the die after it was made and therefore after any true doubling would have happened...