The dovetails are modern machine made (starting at least 100 years ago and still to this day) and the drawer looks like pine (possibly an oak veneer? You should be able to see) while the cabinet looks like oak, also possibly veneered inside and out, and the shelf actually could be a later add on. The back is consistent with the sides in grain and varnish and unless you can see something about how it's attached, I think it's original, and that shelf with the squared wood bracket was added. It's all mass market for many reasons, one because the wood under the top is grooved for drawer construction, meaning pieces were used interchangeably when assembled in a factory. I'm guessing 30's.
|