If that’s the typical concrete? Consider the patina as part of its charm. Concrete is porous and will absorb everything. It’s also a base pH, so acids used on it will etch and pit it. Contact a local custom metal worker to create a support cradle for it with new legs.

I don't like your idea. Too much risk; too little reward.

I was worried mostly about the structural integrity of the legs, so maybe I'll see if I can clean them up and get a better idea how solid they are. It's cast iron, with, I assume a porcelain glaze...but it does look like it's got a good bit of etching in it. Is that a thing? concrete over cast iron?

It would be porcelain over cast iron....you can use paint stripper on both the legs and the sink, won't hurt and will clean up the paint.
It's a great sink and the legs are wonderful!! I hope you can save them!

Having hot on one side and a cold spigot on the other side with no mixer will need altering and a plumber too. This project will likely cost you more than purchasing a refurbished one or a replica.

Well it's all moot anyway. I just realized that to make that sink useable, the back would extend higher than the window seal. So I guess it's going to remain a basement sink after all. Unless anyone has any other suggestions

This would involve changing the window above the sink, but you might bookmark it if you ever decide to follow up on your idea:

More pics (I don't know anything about the architect, and I'm not advertising for them--I've always loved this kitchen transformation :)

If you do decide to strip it, make sure you have lots of ventilation. I once stripped a painted over cast iron bathtub in a tiny studio apartment, while living there. For a few days, I had to stay away all day and then sleep with my head out the window!

Try Zud scouring powder. I find it at the hardware store and some grocery stores. It is heavy duty for porcelain sinks that have lost their protective coating and absorb stains easily. Don't use it on a new sink as it is so strong it could damage the coating.

Awesome! Thanks!