60-70ies Seamaster screw-down crown - understand concept of water proofness

Hi all! Great to be a this wonderful place of watch enthisiasts!
I'm trying to understand in detail the waterproofness concept of the screw-down crown from the 60-70ies as found on many Seamaster models, e.g. 166.088 or 166.024. (Part number 069ST42062). This is what I'm talking about:


Of course I could tear down this one to see myself... eehm well better not.

So, how many o-rings does the crown have? Are these even o-rings? Do the o-rings go around the shaft of the tube or at the end face or both? Here's a sketch to visualise my thoughts. I hope there's an expert on the forum who can guide me in the right direction!


Thanks a lot & a great day to you all!
J

Thank you all very much for the input! Indeed I have seen a few of the links before, but never found something specific about that typical 60ies Seamaster screw-down crown…

I guess it probably is as @Dan S is proposing: o-ring that goes around the tube.

One question is still, if the o-ring is squeezed in some way when screwed down. And if yes, then how exactly.

Maybe we will still find the answer!

Thanks @Omegafanman for the Ploprof link. This one seems to have two o-rings, and the smaller one supposedly goes on the step and squeezes in there. While the larger one goes around the the diameter.

Thank you very much for the clarification!