The flatter top profile to the bell does suggest 50s. I'll have to consult my notes to see which ones. *edit* no joy on the flatter top profile of the bell because my note says it was the Hollow Block which had more of those, and yours is clearly no Hollow Block. If you don't know what that means you need to read that stuff. It is possible (but not evidence based) that it might increase the probability that yours is a Large Stamp -- the variant without the three dots and not the Hollow Block. But to demonstrate that to us, you need to measure the height and it must be 1.75" or more. That's in my writeup as well.

In the second photo, yes that's a more "modern" bell shape. What you describe as machining visible on the bell is due to lathe chatter (from what I can see of it) and this is more common in pre 1960s cymbals but doesn't go away entirely. The shift to having more or less lathe chatter (both in the proportion of cymbals showing it, and the degree of chatter) is gradual rather than some sudden change.

I measured the stamp at 1 & 3/16"

Well not a Large Stamp then. But 1 & 3/16 isn't the expected measurement for the late 50s small stamp. It is the height of the early 60s stamp which should have the three dots. The late 50s small stamp is 1 & 1/4" (aka 30mm or so).

I've seen (and own) cymbals with 60s stamps which are so weakly pressed in that one or all three of the dots may be missing. But never on one as clear as yours.

Note that from the measuring I've done (with cheap plastic vernier calipers and placing pieces of masking tape just beyond the top and bottom of the stamp paying very close attention to just what the topmost element of the Ottoman area really is) I'd say that the 1 & 3/16" and 1 & 1/4" are approximate. Perhaps reported to the closest 1/16" of an inch because those were the divisions on the measuring device?

So consider the possibility that yours might be closer 1 & 1/4" instead. Just that extra 1/16" makes a decade of difference (with poetic license). :)

Thanks again Zen. I re-measured in the daylight just now and I would say that the stamp is spot on 1 and 1/4". The hole is 7/16" or 11 mm and there is no lathe chatter on the bell, the bell is flatter and less modern. The bell is strange to me. It had stages of lathing and the rings are separate as they progress down the curve of the bell. Fascinating!

See pics.

The thing I need to learn more about (beside everything) is about the ink stamp. since I didn't start purchasing cymbals until the mid 70's, I have no idea if A Zildjian ink stamped their cymbals way back then. I thought I read someone say they did. All indications so far have me believing I've got a find from the mid to late 50's. But if they did not ink stamp back then, I may have a late 70's cymbal but I have never seen a cymbal that looked like this new in the 70's. I looks much older to me, even older than the 60's........just speaking from experience only...which doesn't say much!..lol

I posted an ink stamped cymbal which predates the Trans Stamps. So they were putting ink stamps on from at least the mid 1940s. It is post #3 in this very thread. In addition to BOUNCE, I've seen MEDIUM and other designations. How much evidence do you need?

OK. that Bounce cymbal photo you posted looks like you bought it new last week. I got confused.................

Not my BOUNCE, but the owner is a friend. And yes it is confusing. First because it looks brand new, and second because you have had lots of information thrown at you at great speed. Thanks for being a good sport.

I've been trying to put together a complete beginners introduction for a year or more, and not only did I finally get something started but I've got some new ideas for re-writing and other sections already.