[BigJJ]

The lack of any stamping is frustrating.
However, if the ring were resized, it may have lost it's stamping.
Also, and perhaps more likely, this was an internal sample at the small Zacko jeweler, or one made for the jeweler's father Joe Zacko.
I have not seen this ring copied, doesn't mean it has not occurred of course.
I see that rings were composed of different materials for different team members and reunion years. This makes sense as the guys were footing whatever bill they could afford - some gold, some sterling, some metal. And when they could afford it. Some members bought rings at earlier reunions, some later.
It is interesting that this ring is married to a letter from Latone to Joe Zacko, the jeweler's father.
And I reviewed the Worthpoint listing, which states, as noted above, that Joe Zacko was the jersey supplier for the team, and the son, was the jeweler who supplied rings to the team in the 1960s. And that this ring came from the Zacko family.
I believe this ring is authentic. And may be considered a salesman sample. Or given the association of the father to the team as jersey/equipment supplier and important booster, perhaps the son made this ring for his father, and it may be considered a team/staff ring.
As noted above, value is tough to determine as not a league issued ring, not made of valuable material, no player inscription/provenance, and no stamping.
But I do think, given the totality of the evidence, that the ring is authentic.