You're in the vintage omega section, there is a forum for Longines. pictures of the backside of the case usually helps
Dam I thought I pressed the longines section before I posted it, small screens on iPhones not good, sorry guys.
Judging by the single picture you've given it looks like a Longines Aristocrat. If so, it will be from the 50's, probably between 54' and 55'
Here is a closer picture of it, am guessing your dating is properly about right it seems to look about 40s early 50s
I've had a better look and from looking at the dial on yours it seems to resemble a Longines Wittnauer. Which is also from the 50's..have a look at the picture below and let me know what you think