At that weight and diameter and production era (late 50s) the likely models are Bounce, Medium Ride (which usually have model ink saying Medium), or maybe Bop or Dance. Probably not a Ping at that weight.
For example, models with ink and their weights in the 1970s 20" 70s A Zildjians with model ink:
[LIST]
[*]ex. thin 1875g (this was a Flat Top Ride)
[*] crash 1642g
[*] thin 1620g*, 1748g, 1748g, 1755g
[*] crash ride 1914g, 1918g, 2054g, 2080g, 2114g (plus a 1943g thanks to nickrobotron)
[*] thin crash 1944g**
[*] paper thin 2087g (seems rather heavy unless they meant paper thin ride not paper thin crash)
[*] medium thin 2010g (plus a medium thin ride 60s stamp 2036g thanks to nickrobotron)
[*] light ride 2130g
[*] medium ride 2200g - 2678g
[*] mini cup ride 2475g, 2951g, 3180g (it seems they came in two weight classes based on other info)
[*] deep ride 2800g - 2950g
[*] ping ride 2850g - 3100g
[*] earth ride over 3500g
[/LIST]
* more likely a thin crash missing the crash ink but the thin ink was still there
** more likely something other than a thin crash at that weight
The late 1950s cymbals were lighter, although I'm still working through my large data set to present a nice summary of the whole picture for every production era and diameter. I just happen to have done the 70s analysis for 18" and 20" recently.
Weights proceed in an orderly fashion with some overlaps and a few as yet unresolved oddities. You can see where Crash Rides fit in the overall scheme. Note that Crash Rides also use the 5.5" diameter bell (and they share this with Crashes) in the 1960s. Medium Rides used the 5" bell. I haven't yet traced that larger bell die back into the late 1950s on Crash Rides or Crashes but I can't rule it out. There is a similar 5.5" diameter bell in use in the mid 50s which I have on a 22" Large Stamp at 2800g. However, the bell shape is different from the 60s one used on 18" and 20" Crashes and Crash Rides. The other difference between the Crash Ride and a Ride is greater taper (thinner metal) in the Crash Ride to improve the crash.
The attribute to check for factory rivets is how they are finished on the underside. That doesn't show in your photo. In fact I can't tell if they are split rivets (which would be non factory) or tube rivets (which could be factory). Factory rivets were finished with the special tool Zildjian used which makes star shapes.
[img]https://black.net.nz/avedis/images/factory-flared-rivets.png[/img]
If those are tube rivets with the star pattern then they pass the factory test. Otherwise they don't pass the factory test. Note that the holes could be factory and the rivets replaced later on.