Longines Pocket Watch Gold 18k «Grand Prix Paris 1889»

Hello
I own a beautiful Longines pocket watch gold 18k with serial number 961129 in the 2 cases The diametre, without crown, is approximatly between 34/36mm because I don´t have a precision instrument to mesure it. Through this number I found that the year production is approximatly 1899. The case has the Longines logo EFCo - Longines and inside there is written «Grand Prix Paris 1889», 3 gold medals and 7 silver medals.
Is normal in Longines that the serial number is in the case and also in the movement but in my case in the movement is only the brand Longines, as you can see in the photos. I saw others Longine pocket watch, before 1900, without number in the movement. Why?
My doubt: belongs this movement to the this case? Is it a original Longines movement?
Thanks you.
Regards

I'd bet it left the factory as one piece. Recased watches usually have "extra" screw marks where the screws held the original movement into the case, there's no such marks on this case. If you're movement swapping, the pin set position would have to match as well.

I've seen earlier Longines keywind movements that look very similar.The movement number could be elsewhere on the movement, it wasn't always on the top plate, I've heard of them appearing under the balance or on the opposite side of the movement, under the face. It looks like a nice original unmolested piece..... oil it and wear it!

The watch in the picture is probably all original - that's why the numbers match. It's getting less & less often that we see this, as every time gold goes up the cases get melted and the movements are stuffed into whatever other case will hold them.

Nice watch!

I'm not a pocket watch guy but damn that's nice!

Thank you guys. For a 1899 watch he is indeed in a perfect shape!
How do I know the caliber of the movement?

Well, you might be able to see the number under the balanace wheel..... or you could just ask somebody, say, like me.

And if you did ask me, I would tell you it's a 16 jewel caliber 13.67 (29.6 mm / 13 ligne) that was introduced in 1894.

..... but you haven't asked me yet so don't look at that answer. 😁