MS-65= Gem Uncirculated or above average uncirculated coin with few contact marks and no spots, a really great looking coin
Mint State. The numerical term is given strictly for Numismatic grading purposes.
MS stands for Mint State and 65 is the grade given to the coin. There are several grading levels for a regular strike coin, Mint state being the best with MS grades ranging from 60 to 70 (70 being a flawless coin). You may also see a coin marked PF 65 which simply means the coin was a specially longed proof coin, double struck with a special dye by the mint for collectible purposes.
Well, if you get it certified as Mint State-65 with Full Steps by one of the major third party certification services, it would list (retail) at $55 with no mintmark or $500 with a "D". If it has not been preserved, I doubt if it would quite meet the standards for a Mint State-65 coin, however if it did, but did not have full steps on the reverse, it would catalog for 50-55 cents retail. Certification will cost you about $40.
Mint state means a coin in the same condition as it was when released by the mint that struck it.
If the coin is mint state the retail prices are: MS-60 $50.00/MS-61 $53.00/MS-62 $$60.00/MS-63 $108.00/MS-64 $219.00/MS-65 $500.00
Mint state means: no wear at all, the condition is as it came from the mint.
You're referring to MINT MARK - please see the Related question for more. "Mint state" describes a coin in brand-new condition, just as it came from the mint.
Mint state retail values for this coin are: MS-60 $480.00/MS-61 $588.00/MS-62 $630.00/MS-63 $1,270.00/MS-64 $1,710.00/MS-65 $5,490.00
If I understand the question, the term "Mint state" refers to the uncirculated grade of a coin, not one of the United States
"Mint state" describes the condition of the coin, meaning that it's never been used in circulation.
It isn't an error, on most coins, the Philadelphia Mint didn't get a mintmark until 1980. So your coins were simply minted at the Philadelphia mint and not an error.
Mint condition, Mint State, & Uncirculated all mean the same thing. Unused, no wear, as in the same condition as from the Mint when the coin was struck.