Your picture cuts off the caliber number at the center of the movement where there is an Omega sign and 4 digit number. My guess is that it's a caliber 1360, manufactured between 1978 and early 1980s. On the back cover is the ref. number 592 xxxx, (not serial number).
This is a quartz watch, so it cannot be made in 1915/1916.
At least the watch looks legit. Serial numbers are generally on the movement, and would be 8 digits in this case. I'm not sure if these quartz movements have them, maybe on a sticker or something like that. Actually, it could be on that small round sticker below the battery clip? I think I've seen the 8 digits divided into two rows. It may be pretty hard to read.
The 592.xxxx will tell you exactly what model it is.
5 = Lady's Watch
9 = Electronic
2 = Non-water-resistant Calendar
XXXX = Case Reference and sometimes, distinct De Ville model ("Vincennes", "Orly", "Ile de France" etc)