What kind of ETA7750 is that?

[andries]

Well, movement is definitely made by ETA. But I have no idea who did decoration.

Ok, I finally found back the doc from ETA. The top grade also comes with Glucydur balance wheel, so this one must be elaborated.
https://secure.eta.ch/CSP/DesktopModules/ViewDoc.aspx?DocId=173&DocType=DT

Access denied

 

[QinetiQ]

Access denied here as well

 

[andries]

I figured it out. You have to start from beginning - go to eta.ch, then support center then search for caliber. It appears that only difference between Chrono and Top grade is a number of positions it is being regulated in. Mechanically they are the same.

 

[Wiz]

https://secure.eta.ch/CSP/DesktopDefault.aspx

Click on "Technical documents" in the menu at the top, then write "7750" in the option 2 search field, and then choose the "Manufacturing Information" document from the list.

It appears that only difference between Chrono and Top grade is a number of positions it is being regulated in. Mechanically they are the same.

The chronometer grade is also more precise, but yes, the parts are the same.
Note that on other movements top and chronometer grades may use different parts.