Hi,
antique is ill defined. From the style I would say 1920ish to 1940ish, though style periods may be different from country to country. I also think I see a phillips head screw above the lock, those just came up in these periods.
If you believe it to be older: how is it joined? Just bud&dowel, or anything more sophisticated as e.g. dovetail?
Greets
Namxat