Welcome Pierre,
I'll be interested to hear what Zildjian say as far as model goes.
There are production clues as to when it was made.
The pressed in die stamp is what Bill Hartrick called a 1960s stamp. The hammering on the top is what we associate with 1960s hammering style. Small round hammer marks in a concentric ring pattern. The lathing is also what we associate with early 1960s in that the width of the grooves isn't as consistent as later on (say the 1970s) but is less variable than the 1950s. So those three things line up as 1960s. You can read up further via the link in my signature. The different production clues don't always line up, but when they do that's a good sign that the estimate of production era is robust.
The actual model is something I don't have as much information on. Once the model ink is gone it's harder to pick. I'm collecting info on weights and any associated model ink. Alas, it seems like over 90% have lost their model ink but there are a few examples in my database:
MEDIUM THIN 2010g (1970s)
MEDIUM RIDE 2400g (1970s)
MEDIUM RIDE 2632g (1980s)
Excluding obvious crashes (cutoff at 1800g see below) the average weights for the 50s and 60s is 2000g (n=33) although actual weights are still variable even within a particular model class. The target weight range for a 20" MEDIUM RIDE might be plus or minus 100g (tolerance of 5%) so we expect to find a 200g range for them. But we don't know what the target weight ranges and tolerance used to be in the 1960s. My estimate of 5% comes from a few different diameters, but I haven't revised it recently given new data I've collected. Zildjian have very recently started discussing the target weight ranges and writing the weights under the bells of some models.
The weights increased in the 1980s such that what was called a HEAVY in the 1960s became a MEDIUM in the 1980s. I've also got a quote from Zildjian talking about this obesity epidemic. Zildjian reset the target weights in 2013 (also documented on my site) back down again.
The weight of yours is right for a RIDE from the 1960s, but there were other models available (Be-Bop, Bounce, Crash, Crash-Ride, and Ping are named models from that era). It's unlikely to be a crash because those are lighter again (under 1800g). One distinguishing feature of model can be the diameter and height of the bell. I'm not good enough at judging the size from photos, but that bell looks like it might be the 5.25" diameter one rather than the 5" one. There are also 5.5" bells which based on weight is associated with crashes. Going by the weight of yours and the look of the bell, I don't think it is a 5.5" one. But as I say, I'm not up to speed at picking bell diameter from photos yet. According to Zildjian the crash-ride models and crash models would have a larger diameter bell, but I haven't yet found out the production years for a model explicitly labelled crash-ride. They do appear in a 1970 catalog. And it's not just bell size and weight. There are probably also differences in the level of curvature in the bow.
Also a little request. I'd say the stamp on yours is either about 30mm or a little under 32mm. But if you have the ability to measure it accurately enough I'd love to know. I doubt it is a 38mm one based on the look of it, but if it is a 38mm one then that would be great to know because I'm always after evidence which contradicts my current theory. That's how we collectively improve the science. There are examples of how to measure and where to measure on my site. Check out the 1960s. And metric is fine.
Bop iT / Til U Drop iT.