I believe this is 100% legit, This site US Coin Guide
https://coins.thefuntimesguide.com/...llar-errors/ States: 1972-D No FG
Kennedy half dollarThe 1972-D No FG
Kennedy half dollar is known as the rarest of these errors. Perhaps a few hundred may exist.
Even in circulated condition, the 1972-D no FG
Kennedy half dollar value is around $300 to $500.
The record price paid for a 1972-D
Kennedy half dollar with no FG initials was $2,485.13 in 2016 for an MS63 example slabbed by Professional Coin Grading Service (PCGS).
So I guess ones enthusiasm on this type of coin is a personal issue. I don't know about you but $300-$500 excites me. Coop $300-500 doesn't excite you? By
US coins they are not very common. I searched over 2 million dollars in half dollars and found a few of these. This was my second best one and now Minimarine has it. The value is awesome, but putting one into someone's collection who doesn't have one is even better specially when I consider them a friend.
"LOVE THE HUNT!"