Pedestal sink
Don't be discouraged!
I installed a pedestal sink in nearly the same situation as yours several months ago, and I'm very happy with the result. My house was built in the late 1920s and, like yours, it has the supply and drain lines in the floor rather than the wall.
I used a chrome s-trap from the hardware store and an American Standard Williamsburg pedestal sink from a local big box store. As I recall, there's reasonable amount of adjustability in the sections of the s-trap, so you have some leeway if you're willing to live with a sink that might not be absolutely centered on the drain or supply line.
The fact that the pedestal base does not hide all of the lines does not bother me at all. In fact, I think most vanities are ugly, and since they're commonly made from some sort of particle board, they can become sources of odor and or mold. Pedestals are a much nicer option.
My logic is that since you're not adding or even moving an existing fixture, your code compliance is grandfathered. I don't think most code officers would make you rip open a wall to connect to a vent line for this project. I'm sure that there is a vent stack somewhere close by that has worked fine for almost 80 years.
I'll post a few photos tomorrow, if I can find the batteries for my camera.
Good luck!