Hi there =- here's a comparative video that I made of my 4 22" A Zildjians (please excuse the poor lighting - my studio's natural lighting is not great and the Zoom recorder's camera is not eitherCooked Egg) - they all bear the 60's stamp although 2 of them are lathed and hammered very differently to the others. The lathing on those 2 are shallower and somewhat denser than your typical 60's lathing. At some stage someone suggested that they may be 54 stamp cymbals - I am not sure. Anyway, each of them sound markedly different to the others but in a good way. Sequentially, the weights are roughly 3550g / 2470g / 2800g / 2540g. The last two are the possible 54 stamp candidates.

[ame]https://youtu.be/QyYLdUndVlk[/ame]