These type of artifacts are not uncommon in older cymbals. They vitually disapeared after the early 1960's. Various foundry imperfections such as ripples, erstaz dents, charcoal pits, and a few others are among the notables. These are most commonly seen in the 1950's era. I have many photos of such artifacts in my archives.

They add visual character to a cymbal.

ive got a late 50's 18 avedis ,1220 grams. it has that same dimple and ripples in the base of the bell.

mike

thanks for that. So do these stamps indicate 50s rather than 60s?

BTW, they each weight about 1000g. The top is higher pitched than the bottom and interestingly the top is a slightly smaller diameter at slightly under 15"

They're 60's.

Thanks again. So maybe a late example of factory flaws? I agree that they add character.

And is one of the cymbals being slightly smaller common? it's about 0.11" smaller in diameter