Can anyone identify this watch? I'm stumped!

[Rolesor]

Hello all. It's been a while since I posted last. Long story short I met with the son of a collector who has had these watches passed to him. Some really cool pieces. Patel, vacheron, zenith and Tons of Rolex including one I have never seen before! It looks like a Paneri? Can anyone advise what this thing is? I have no reason to believe it's not real as the rest of the collection was 100% solid. The back was a clear case back and had Rolex written all over it.

Can anyone give me info or I.D it for me? I have my eye on another piece but my friend wants that one if it checks out and the price is right.

Only thing to add is the collector lives in Hong Kong and the watch is definitely older. Thanks in advance guys!