I am sorry to chime in again on the 2007-D Kennedy Half Dollar that looks as if it is a Struck Thru Reeding Error but this tidbit has been bugging me about the Reeding and I believe it is relevant to the discussion! I also apologize for the lengthy post and hope it does not sound too confusing!
I have mulled this over in my' head many times, have pulled out several Kennedy Half Dollars I own (1964-P and newer ones) to check the Reeding on them and believe I have found a serious deficit in considering the Error to be genuine. If you note the size of the possible Struck Thru Reeding Error impression on the Obverse of the coin and compare that Reeding to the Reeding applied to this coin's planchet by the Mint before it was struck into a coin, they don't appear to match up size-wise between the valleys and ridges. It is hard to get a width comparison of the two but believe that the Reeding impression across the Obverse of the coin, is not as wide as the Reeding used on the 2007-D Kennedy Half Dollars. Now I am pretty sure that the Mints made at least one change (maybe more) to the size of the valleys and ridges of the Reeding on the Kennedy Half Dollars during the 52 years they have been minting them (i.e. from smaller widths to wider widths of the valleys and ridges). It is my belief that the change or the most significant change was made during the change-over from 90% Silver to Copper-Clad planchets but I could be wrong. Based on what I see or my perception of the Reeding impression and the Reeding on the edge of the coin being different, I now believe that the Reeding impression across the Obverse of the coin, may actually be a Reeding impression from a Washington Quarter (added) or from an earlier Date minted Kennedy Half Dollar but again, I could be wrong. If the Reeding impression in fact measures the same width-wise and the width or distance across the valleys and ridges are the same as on a Washington Quarter (added) or earlier Date minted Kennedy Half Dollar, then it is highly probable that the Reeding impression (possible Struck Thru Reeding Error) did not occur at the Denver Mint!
In closing, I will say this. I hope that the O.P., port ewen ace sends the coin to Mike Diamond for an Expert assessment and believe it or not, it is my hopes for the O.P. that I am totally wrong in my assessment! There are a few Error and Variety Coin Experts that I do not trust concerning assessments of Error/Variety Coins but even though it has been a long time since I have talked to the following Experts on the phone, I totally trust assessments by Mike Diamond as well as Mike Byers, Fred Weinberg, Ken Potter and James Wiles as well (although I can't remember if I have ever talked with Mr. Wiles) and especially Larry Briggs that helped mentor me about coins when I sat in with him at his' Coin Show tables.
Frank