HELP request: Rolex Movement identity

[Realdeepdiver]

Hi Everyone,
I am trying to find out what info I can for this movement as a build for my wifes birthday. I purchased this vintage movement but have come up short on any info online about it. I am hoping if someone can identify it or point me in the right direction for more info.

I am trying to find a case for it currently. So far I have only found a (questionable at best) Chinese case that might fit it.

So far the info I have found is:
Vintage rolex movement 1920 model size 10 1/2 -h 3235 balance moves then stop need to clean, i think it will fit 6420 model case take a look what you see is what you get thanks for viewing. For parts and restoration surely its authentic Rolex movement. And also some missing parts.

[CTech]

This looks like a mid-1950s movement that would fit in a 20mm outside diameter case. It could be one of the 1300 caliber series, so it might be 1301 under the balance not 301 as identified in the original advertisement.

Here's a watch with an identical movement in a DS&S (Shackman and Sons) UK made 9 ct case:

https://www.worthpoint.com/worthoped...-9k-1476746628

Shackman and others made cases like this for a number of manufacturers in the 1950s and 1960s so you might be lucky and find a suitable case that originally had another manufacturer's movement inside such as Omega, IWC, etc.

[Realdeepdiver]

CTech you are amazing, thank you so much that was exactly what I was looking for!!! Have an awesome rest of you week and I am going to start case hunting.