Stem and crown for Omega Seamaster ref. 2254.5000

Hi all,
I am trying to find original stem and crown for this S/S model (I hope I got correct ref. #) (case #.: 168 1640), but I can find crown and no stem - is there any source where I can get mounted crown already on the stem complete?
Or a source where they have both at the place...???
(I have got a watch with broken off and lost crown and then broken stem while trying unscrew rest part of the crown).

Any help will be appreciated mutch!

The stem is simply a standard ETA 28xx stem.

But then probably need to cut it to the right length - right?