Your serial number puts your FN 1910 into about the middle to late 20's.
Also, your slide should read:
FABRIQUE NATIONAL DARMES de GUERRE HERSTAL BELGIQUE
The type face and style of the lower case "de" decides the approximate date, since some bunch of rowdies destroyed most of the records in and around WWII.
There are also people who have made some study of the proof marks, so a description of the proofs (or pictures) might help.
In any case, they were well past 400,000 by the end of WWII, so you have a 12(7) eligible pistol.
I love the 1910s, they were designed to be dual caliber. Simply by changing the barrel to a 9mm short / .380 ACP barrel, you have a .380. The caliber markings on the pistol are only found on the barrel. If you want to make it restricted, there are still plenty of factory .380 barrels around to do that with. Or you can give this pistol as it is to a brother-sister-wife-son-daughter who has their RPAL, and they get 12(6) but only for that pistol.
While the FN 1910s are not particularly valuable pistols (with a few exceptions), they are surprisingly accurate, reliable and compact. They were popular for over 70 years for a reason.