Judging from the cottered crank, I am guessing it is a European built bike. Maybe from the early to mid-50's? Looks fairly similar to some German (Stelber?) built J.C. Higgins. Check the bottom bracket shell for a serial number. I'm not great with date codes, but some one here may be able to crack it for you.
Not sure if the wheels are original to the bike, but I would also check out the rear hub. If it is an F&S Komet, which is a strong probability, it should have a date code.