Help verifying date of my Grand Prix 1900

[Tymorial]

This belonged to my great grandfather. My grandmother told me this was from the 20s but I think it's from 1911. My understanding is that watches from back then had different serial numbers on the case and movement. I used the lookup chart and it seems the case was made in 1908 or 09 and the movement is from 1911. Either that or these are from separate pieces?

I know it needs a service. I was gifted this recently.

 

[Tymorial]

No one?

 

[gatorcpa]

T Tymorial

I used the lookup chart and it seems the case was made in 1908 or 09 and the movement is from 1911.

It is common that there is a gap of several years between the date of manufacture of the movement and the case on early Omegas.

For your purposes, you can assume that it left the factory in 1911.
gatorcpa