I can only see one edge, and the wood doesn't appear to be plywood, just looking at the photos the wood looks to me like it has an oak grain. That and the fact that there are no screws in the hinges makes me think it might be a lot older than it's being given credit for. In America screws were hand made one a time well into the 1800's, by 1840 the turret lathe was invented, but a screw making machine derived from that didn't appear until 1870. If that comes from Europe, and I suspect it does, they had screws earlier, but still, the fact that the hinges are either riveted or nailed on makes me think older also. Also the hinges look to be rococo to me, which doesn't mean much, but here is the definition of Rococo.
Rococo1. a. A style of art, especially architecture and decorative art, that originated in France in the early 18th century and is marked by elaborate ornamentation, as with a profusion of scrolls, foliage, and animal forms.
All that, and the fact that the hinges appear to be hand made, makes me think this possibly dates quite a long time, and perhaps you have a very real treasure.