need help in finding a pusher cap for an Omega Speedmaster pre-moon from 1965

Dear fellow tinkerers,

I am looking for a pusher cap for a 1965 Omega Speedmaster Pre-Moon chronograph. I am not able at the moment to correctly identify the part number nor the correct pusher size, since the watch is not in my hands. Yet, doing some research, I was able to find the following information:

Caliber: 321
Omega reference Number: 105.012-64 (or 65) - Serial no.22827xxx (so this should set it to be 65... ?)
I was told the part number should be 7889666666 (but honestly, not being an omega expert, I have no idea how to use that number. Any research brings to nothing
The dimensions of the pusher should be 5x3mm, and according to Speedmaster101.com:

"Original pushers on this reference are 5mm wide and 3mm tall and are known as Short and Fat pushers, or mushroom pushers. The original ones have fat necks when compared to service replacements."

Source: https://speedmaster101.com/105-012/

I did find a pusher, but it is stated to be for a 105.003. Dimensions given are similar but not exact:

Pusher cap 4.5mm
Mid section 3.3mm
Part that fits into the case 2.36mm

I added some unfortunately blurry photos to this thread, to to show the pusher with the missing cap. The watch is not being worn at the moment. The stud inside the pusher appears to work correctly, so apparently no spring got lost. Yet it seems there was supposed to be some kind of sealing gasket on the pusher itself?

Thanks for the help, appreciate any information.

You need a cap and the metal ring that fits into the pusher to hold it in place. The pusher will have to come off either way to fit it If you can find one that is.

P.S
Just realised we have been in contact before 👍 There is a thread somewhere regarding these pushers, I will try find it for you.

Cheers, Michael

thanks Michael. Not sure if we have talked before, this is my first post here... anyway any help is appreciated.

If this can help, as I said before I did find a ocmplete pusher on eBay. Attached the screenshot. I do not know if this is correct, though

We have talked through eBay, the pusher above is mine and I am sure I took it off a 105.003 but I could be wrong.
Here is the thread I was thinking about
https://omegaforums.net/threads/speedmaster-105-012-pushers-repairable.96574/

Like you say, the measurements of my pusher are>
Pusher cap 4.5mm
Mid section 3.3mm
Part that fits into the case 2.36mm

aha! then you are the right person indeed! Now I remember you! It was about another Omega, though.... Anyway, do you think your pusher should fit? As per the other thread you linked, apparently there are several parts missing in the pusher I need to fix. I believe yours is complete, right?

I believe the pusher cap on the 105.012 is 5mm wide but mine is 4.5mm, so for now I do not believe it is correct for you, but as always I am happy to be educated by a kind member on here.
Cheers, Michael

Looks like an Ed White pusher, not a 105.012.

Thanks, I will look into it

I managed to find a video showing a tomography of the Omega Speedmaster worn by Eugene Cernan on the moon... Soo you can clearly see the structure of the pushers which I believe is identical to the watch that I have now in for service.

I got the watch in my lab now so I managed to take a better pic of the pusher with the missing cap.

Looks like you need more than only the pusher cap..... Good luck ! Kind regards. Achim

yeah probably the whole pusher. The stem inside the pusher assembly does work though. I guess it is missing the cap, the gasket and the stem cover, as per the thread that was linked above, and I attached here.