Yes the K Zildjian Istanbul (and the earlier K Zildjian Constantinople versions) trademarks are struck in at least 3 separate parts. So are the Avedis Zildjian trademarks prior to the Trans Stamps. As a result different parts are pressed in with quite different legibility, and there can be several attempts to strike one portion so you get ghost images of some portions.
The company name is written under the bell: K Zildjian & Cie. Again it is the same for the Avedis Zildjian pre Trans Stamps which have Avedis Zildjian & Co written under the bell. As with many aspects of production, K Zildjian continued the tradition, but Avedis Zildjian changed. The company name written under the bell is sometimes referred to as the "signature of the individual maker" but I don't know of any evidence for that, and the idea of "an individual maker" runs counter to the idea of a factory organized into specific tasks like rolling vs hammering vs lathing which might be done by different individuals. But perhaps somebody else here has compelling evidence which indicates otherwise.
As far as that specific trademark goes, it has what I've nicknamed the saxophone style in the Arabic portion. That suggests it is later in the K Zildjian Constantinople sequence, or early in the K Zildjian Istanbul sequence. The changeover from the word Constantinople to Istanbul isn't as clean as many people believe. There are some examples which straddle the two. It is hard to make out what it says above TRADE MARK on yours. However, it doesn't look like that word is curved and long enough to have been Constantinople. So perhaps is was ISTANBUL, or ZILDJIAN, or it could even be a first attempt at TRADE MARK which was so weakly pressed in they did another one underneath.
You also have & Co. rather than & Cie. I've got a few examples which don't fit the simple sequence of
K Zildjian Constantinople & Cie (pre 1940)
K Zildjian Istanbul & Cie (OS Type I: 1940-45)
K Zildjian Istanbul & Co. (OS Type IIa: 1945-49)
and given that we know that different parts of the trademark were stamped separately it isn't surprising to me that we find novel combinations of different tops and bottoms once we look at enough examples. That's what happened when I started looking into the Avedis Zildjian pre trans stamps where we find combinations of different tops (Arabic) and English bottoms. So a quick overview of the different portions of yours is
[LIST]
[*]The top portion (moon and star) of yours looks OS Type I or II but not III. Note that MADE [SIZE="2"]IN[/SIZE] TURKEY has a smaller [SIZE="2"]IN[/SIZE], and this varies in OS Type I and II vs III.
[*]The Arabic looks late K Con or OS Type I, II, III
[*]The Zildjian & Co looks OS Type IIa (because of the Co)
[*]The TRADE MARK looks late K Con
[/LIST]
Here's another example in my collection which also shows this unusual combination of attributes:
[img]http://black.net.nz/old-k/images/16-838-stamp2.png[/img]
Bill Hartrick (Drumaholic on this board) who did the pioneering work on documenting the old Zildjian stamps may have formally named this one and documented the diagnostic features, but I haven't seen anything published on it. Perhaps he will comment on these examples.