Source for a Flightmaster Crystal gasket?

[Sinnlover]

As above
Does anyone know of a source for a crystal gasket for 910 flightmaster?
I want to change the crystal but I can’t seem to find the correct gasket
Thanks in advance
John

[Sinnlover]

Nobody?
🥴

[Thewatchbloke]

You can buy a genuine crystal plus gasket here but I don't know anyone selling just the gasket, however it is just a large diameter o-ring so measure the cross section of the old one (0.8mm from memory) and order a new one of the correct diameter (inner ø35mm, outer ø36.6mm, again from memory so I could be mistaken).

[Kingstepper]

You can buy a genuine crystal plus gasket here but I don't know anyone selling just the gasket, however it is just a large diameter o-ring so measure the cross section of the old one (0.8mm from memory) and order a new one of the correct diameter (inner ø35mm, outer ø36.6mm, again from memory so I could be mistaken).

I've seen mention elsewhere that some had square and some round cross-section, is that possible/likely?

[Sinnlover]

You can buy a genuine crystal plus gasket Ihere but I don't know anyone selling just the gasket, however it is just a large diameter o-ring so measure the cross section of the old one (0.8mm from memory) and order a new one of the correct diameter (inner ø35mm, outer ø36.6mm, again from memory so I could be mistaken).

Good point!
Will try that
Thanks for the link to the crystal might buy a spare! - edit - done
I now have a spare. I will also buy a generic o- ring to try.
Thanks for the tips

[Thewatchbloke]

I've seen mention elsewhere that some had square and some round cross-section, is that possible/likely?

I've changed a few of these type of crystals on various Omegas and I've only ever come across nitrile o-rings being used. I haven't heard of square section nitrile gaskets being used (and I can think of a few drawbacks) but in the world of vintage watches anything is possible I suppose!

[Sinnlover]

You can buy a genuine crystal plus gasket here but I don't know anyone selling just the gasket, however it is just a large diameter o-ring so measure the cross section of the old one (0.8mm from memory) and order a new one of the correct diameter (inner ø35mm, outer ø36.6mm, again from memory so I could be mistaken).

Thanks for the suggestion Duncan
I
New crystal and gasket installed and it’s brought it back to its former glory.