New SDV but the crystal has popped out

So I finally acquired the piece I've been searching for - a steel case Seamaster De Ville 565 with crosshair and hippocampus caseback 166.020. It's a lovely piece and I really love the dial! It's had a light polish at some point in its life but that doesn't seem to be too recent.



The only problem however is that the crystal isn't secure - I can pop it off with just my fingers, leaving the bezel in place! The bezel is secured to the case adequately and the inner bezel ring seems to fit correctly. The crystal seems to be genuine (it has the Omega logo etching). The bezel simply isn't tight on the crystal. Is it difficult to assemble these bezels the right way or is it more likely that an incorrect bezel crystal for the case has been fitted?

Oops, I meant to say incorrect crystal, not bezel!

Yeah it's definitely the wrong crystal. In this video it's clear that the bezel is fit to the crystal quite tightly. If I remove my bezel and place it on the crystal there's quite a bit of slop between the two.


Where's the best place to buy a crystal from (I'm in Australia)? I believe the part number to suit the 166.020 is 063PZ5072?