Pictures are worth a thousand words. You provided 40. So .. pictures of the front, back would help tremendously. At one time there was only one Mint that made coins - Philadelphia. They had no reason to use a mint mark as everyone knew where it was made. Once new mints came into production those places used mint marks to identify where it was made - D, S as example. Of course, no mintmark still meant Philadelphia. which they later started using "P" for Philadelphia to further confuse people. So don't get confused when there's no mintmark on a coin.
I have a1976 no mint mark and I am quite sure it is a proof so there should be a s i have other proof with the s and they are identical
If it came from a proof set then you may have something. If it came from circulation, then no. Post some photos for better information.
Post #8, #21 and others provide the explanation. You must have missed it when you were reading through the thread BTW: your coin does have a mintmark.
I have a quarter with Washington’s face smeared. It definitely cane from the mint this way. Is there any value in this quarter?
You would need to post pictures. If it is truly smeared though there is very little chance that it came from the mint like this.
Did you read the thread through? A 1976 nickel with no mint mark was minted in Philadelphia, they made over 327 million of them. Very common, worth five cents.