As others have said, this is a very fine watch, with a high-grade caliber. The regulator attests to that, as also does the jewelling (how many jewels?), some of which are set in gold "chatons" screwed to the plate.Here is the omega pocketwatch I was given a few weeks ago. It belonged to my great grandfather who was a captain in the british army in WWI
I suggest you should NOT try to check the timekeeping before having the watch serviced, cleaned and oiled. After so many years, the oil has no doubt set or dried, and it would not be wise to let the watch "run dry".
Also, it is a very good idea to keep the chain on the watch in order to avoid dropping it, and ruining the dial... or worse. These do not have "shock protection"!
This is a very fine timepiece and a great heirloom, very much worth restoring. You're lucky!