Opinions on these aftermarket flat-feet Speedmaster crowns

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I found these 24-tooth flat-foot aftermarket crowns being sold on eBay:

https://ebay.io/m/VLGm8A

Would these be safe to use on a vintage Speedmaster or would they pose the same water resistance risks as installing an original vintage crown?

 
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what do you think how good the rubber is after 60 years? 😉

edit: ah sorry, you said its aftermarket. Depends on how much you would trust an aftermarket part for your several thousands worth watch.
 
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Is that a no then? 😁
Yes, it`s no.
Within 3 -6 months you will see a real one on the bay or here on OF.
 
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Yes, it`s no.
Within 3 -6 months you will see a real one on the bay or here on OF.
What do you think about rebuilding an original one with new seals for water resistance?
 
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What do you think about rebuilding an original one with new seals for water resistance?
Takes someone willing to do the work and someone willing to pay. They're not designed to be repairable.
 
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What do you think about rebuilding an original one with new seals for water resistance?
I did it twice on a A2 type crown, it`s a "monks job" and can take 1 -2 hours prying out the old O rings goo/tar. Once cleaned it is easy to push in 2 !! new O ring in size 3.8 x 2.4mm available from sample sets on ebay. Your tube outside should measure 2.5mm diameter so check it first.
Both cleared the 3 atm test but it is not work an Omega watchmaker can do as per Omega rules, nor is it something they have time for.


https://omegaforums.net/threads/would-need-an-advice-about-a-speedmaster-321-crown-a1.99931/

Inside of a crown when you remove the round "lid" taht i opened for science sake so dont do that yourself it is very very difficult to get that lid straight back in ;
 
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I did it twice on a A2 type crown, it`s a "monks job" and can take 1 -2 hours prying out the old O rings goo/tar. Once cleaned it is easy to push in 2 !! new O ring in size 3.8 x 2.4mm available from sample sets on ebay. Your tube outside should measure 2.5mm diameter so check it first.
Both cleared the 3 atm test but it is not work an Omega watchmaker can do as per Omega rules, nor is it something they have time for.


https://omegaforums.net/threads/would-need-an-advice-about-a-speedmaster-321-crown-a1.99931/

Inside of a crown when you remove the round "lid" taht i opened for science sake so dont do that yourself it is very very difficult to get that lid straight back in ;
That is an absolutely stellar answer, thank you!
 
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I did it twice on a A2 type crown, it`s a "monks job" and can take 1 -2 hours prying out the old O rings goo/tar. Once cleaned it is easy to push in 2 !! new O ring in size 3.8 x 2.4mm available from sample sets on ebay. Your tube outside should measure 2.5mm diameter so check it first.
Both cleared the 3 atm test but it is not work an Omega watchmaker can do as per Omega rules, nor is it something they have time for.


https://omegaforums.net/threads/would-need-an-advice-about-a-speedmaster-321-crown-a1.99931/

Inside of a crown when you remove the round "lid" taht i opened for science sake so dont do that yourself it is very very difficult to get that lid straight back in ;
I was able to purchase an A1 crown from @speedb who has kindly dissolved the original gaskets. Do you know where I might be able to find the correct sized o rings to fit the A1 crown?
 
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I was able to purchase an A1 crown from @speedb who has kindly dissolved the original gaskets. Do you know where I might be able to find the correct sized o rings to fit the A1 crown?
O ring/gaskets for crown on ebay, only use round ones - flat gaskets dont work here - and look for 3.8x2.4mm and 0.8 thickness or similair. Be carefull opening them as mine had the sticker on the wrong side so they all fell out....🤬;

@speedb curious to learn what solvent you used and for how long, that may be alot easier then prying them out !

 
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O ring/gaskets for crown on ebay, only use round ones - flat gaskets dont work here - and look for 3.8x2.4mm and 0.8 thickness or similair. Be carefull opening them as mine had the sticker on the wrong side so they all fell out....🤬;

@speedb curious to learn what solvent you used and for how long, that may be alot easier then prying them out !

That is absolutely brilliant! Is one enough or did you use two?
 
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O ring/gaskets for crown on ebay, only use round ones - flat gaskets dont work here - and look for 3.8x2.4mm and 0.8 thickness or similair. Be carefull opening them as mine had the sticker on the wrong side so they all fell out....🤬;

@speedb curious to learn what solvent you used and for how long, that may be alot easier then prying them out !


Left in acetone until i was sure there was no more gasket, acetone causes the gasket to swell and eventually disintegrate and does not leave any residue or damage the metal components of the crown. It also gets rid of any old grease or dirt.
 
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Left in acetone until i was sure there was no more gasket, acetone causes the gasket to swell and eventually disintegrate and does not leave any residue or damage the metal components of the crown. It also gets rid of any old grease or dirt.
Many thanks, will give that a try next time !