Your caliber 268 (with a subsecond dial, I presume) is an evolution of the brilliant line of 30mm diameter movements launched in 1939. These afordable (but for how long?) movements are wonderfully accurate when properly timed (around 5 seconds variation/day max.) and are also beautiful pieces of workmanship. Notice the beautiful copper-colored finish and very fine lines on the movement. Your model should also be equipped with an incabloc protection on the balance wheel jewel. I own several models of the series (two cal. 265 and one early 30T2 of 1939) : I'm always wearing one of them, prefering them to the flashy Rolex of my younger years. Oh, by the way, if you want to check out beautiful pictures of early Omega movements, go visit www.joseph-watches.com
-- definitely on the expensive side but very well photographed.
By the way, "swiss" at the bottom of your dial probably indicates that the dial is original vs redone (though not systematically).
Oh, and you can also find quite an important colection of original omega crowns for sale on the site www.ofrei.com. Match the crown model with the ref. # listed inside the backcase of your watch.
Hope this helps.
D.