So we are tearing apart a small powder room in a 1950's home...and have hit a bit of a snag with the existing plumbing. We want to install a bottle trap drain with the new sink, since the plumbing will be exposed and we think these drains look cool. Something like this:



The problem is the drain stub coming out of the wall is 2" threaded iron. The drain we like (above) looks to have a 1 1/4" outlet. So I'm wondering what options I have? I'd hate to remove the existing stub, since it would require cutting into a healthy plaster wall. Any ideas?

Thanks...