Grading: My guess, genuine, scratched (left of date). Possible PVC on the horizontal shield lines as well. AU50 details.
Dates were punched in by hand. It is common for them not to be level and for the placement to vary significantly. The date placement on this coin looks within the bounds of normal to me.
I can see a possible RPD on the first two digits, but couldn't tell you for sure without much better photos. I would caution that many dealers do not know the difference between an RPD and strike doubling. 1868 over 1888 is impossible. Perhaps that was just a typo on your part. In one part of your post, you referred to this as an overdate. It is not. An overdate involves two different years. The correct terminology here would be repunched date (RPD), if in fact it is present at all. See if you can post greatly enlarged photos of the date.
The appearance of the date with the last digits flatter is also common, and due to grease in the die.
Die cracks are very common on shield nickels. On the reverse, the most common place to see them is along the tops of the letters as seen on your coin.
A previous poster also said:
"early mutable RPD coin ..IE the weak date was spotted early in the life of the die and then corrected with new hand punched numbers which could have obliterated the RPD or created a MPD"
"Mutable RPD" is terminology that sounds invented to me. The explanation is also unsound IMO. There was no weak date on this coin to be corrected - the appearance of the weak date is a grease fill, not a die problem. To my knowledge, dies were never taken out of service and repunched. Repunched dates were created before the die was ever placed in service. The phrase "new hand punched numbers" gives the impression that the original numbers were not hand punched. ALL dates on shield nickels were hand punched. I see no evidence for an MPD on this coin.
#5669313 - 05/10/1203:59 PMRe: NEWP Sheild Nickel. I think it will grade exceptional
[Re: skippy]
doolydooly
I was posting here when you were in diapers.
Registered: 02/23/07
Posts: 3471
Loc: Northumberland UK
Not harsh mate just right i too was flapping about doing to much stuff at silly o'clock in the morning .. Answering *spoon* questions on ebay and stuff .. I know what i was trying to say .. but it did not go down on the paper as intended
Skippy- Thanks for your opinion and for sharing your thoughts. I said the 1868 over 1888 comment because I could not put the thoughts into words and as I was processing the info I've gotten so far, thats what got spit out. I knew somepeople who know what I meant and correct me, and I have no problems with that. I like hearing from people who have been collecting longer than I, gives me more to consider the next time.
If I had the coin I would take better pics tomorrow when I get my microscope/ Camera delivered. I traded it for 2 morgans.
I needed something better and different than my loupes and 60x handheld microscope because of coins from my Uncle that I purchased. Thousands upon thousands of Indian head cents to 1970's lincoln cents. Hundreds of barber dimes and mercs. All the way to 120 Morgan dollars. I like to check every coin I have for errors or varieties. A seller on Ebay had a 200x USB microscope/camera, diffuse lighting, stand, etc. (Things that I will need to get better images. Many of my posted pics are not good and are hard to see in good detail.)
I appreciate everyones input! Like I said, It helps me next time I'm in this situation. Education is never a bad thing.
-Dave
_________________________
"A failed attempt is better than never making the attempt at all." "Don't think..Just Double Tap."
Checking all of your coins for varieties is lots of fun. I got into varieties in a big way. Started with VAMs (before they were popular), and then I discovered shield nickels (which is variety paradise).
As far as what to use when looking, if it takes more than a 10x magnifier to see then I think it's not very significant.
VAMs are my next adventure. Do you know any good books, guides or websites for VAMs? The cherrypickers guide only has some morgans but I would like to find something that lists all discovered/ known VAMs
-Dave
_________________________
"A failed attempt is better than never making the attempt at all." "Don't think..Just Double Tap."
an unlisted mint error for mogans !!!!!!! 
hope you get a good vam .
i too was flapping about doing to much stuff at silly o'clock in the morning .. Answering *spoon* questions on ebay and stuff .. I know what i was trying to say .. but it did not go down on the paper as intended 
